There are lots of ways to deal with thoughts like "I still feel like a piece of garbage". What matters most is that you find a way that actually works for you.
Here's some related info from the F2F course:
Part 1: Guilt vs. Shame
Guilt and shame have healthy purposes, and a certain amount can motivate you to change your behavior for the better. But you may wonder, ”Just how much guilt and shame is it helpful to feel? And at what point do they become toxic and destructive?’ Let's delve into these emotions and try to understand them.
Shame is an emotion that arises when your current view of yourself doesn’t match your ideal self-image. For example, after using P&M, you think, "I can't believe I've done this again!" (with the emphasis on I've) or "I'm better than this!"
On the other hand, guilt follows shame and arises when you focus on your behavior and responsibility. For example, "I can't believe I've done this again!" (with the emphasis on "done this"), or “I was nichshal because I wasn’t careful enough”.
However, shame becomes toxic and no longer serves a useful purpose when it makes you feel helpless and hopeless; for example, when you feel ashamed about something you think you can't change. You may feel this way about using P&M if you've repeatedly tried to quit but been unable to, and so you internalize your shame (for example, "I just can't change no matter how hard I try. I'm a loser. Hashem must hate me."). In this case, the shame becomes chronic and paralyzing. Paradoxically, rather than motivating you to change your behavior, overwhelming toxic shame causes the desire to self-soothe by further indulging in the behavior.
Similarly, toxic guilt is a feeling of an exaggerated sense of responsibility for events that are not entirely under your control. For example, you feel overwhelmingly guilty about wet dreams or thoughts and desires that weren’t really possible to prevent. Like toxic shame, toxic guilt makes you feel out of control. It leads to depressive symptoms and the desire to self-soothe by indulging even more in the problem behavior.
So what can you do to prevent toxic guilt and shame? Psychologists propose a "sweet spot," or appropriate level of guilt and shame that's not overwhelming or destructive and can motivate you to change your behavior.
For example you can:
Talk about your feelings – with trusted and understanding people like your co-pilot, mentor, and supportive friends and loved ones. They will give you a balanced perspective and help you adopt the right attitude to overcoming your problem.
Validate your feelings of shame – that means that you have a good and virtuous ideal self-image. Acknowledge that these feelings are normal and common. If you feel bad about your behavior, it’s a good sign.
Have hope and confidence that you can change – just as many GYE guys have. They prove that it is possible for you to meet Hashem's expectations.
Understand that the power of Teshuva applies to you – Hashem will forgive you. It just takes a few minutes of Teshuva. Small tikunim, mikvah etc. can also bring a sense of closure and that you have “repaired” yourself.
Don't dwell on the past - —and on your previous behaviors once you've done Teshuva. It will only make you feel demoralized and paralyze you from taking positive steps towards change. You can only ever start from where you are now. Dwelling on past struggles with P&M may also stimulate sexual arousal instead of taking your mind off porn and onto something more constructive.
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Part 2: Thoughts on Trial
One way of dealing with unhelpful thoughts is to try to change them, for example by "putting them on trial". Here's a worksheet that can help with the process:
guardyoureyes.com/f2f/w/6.2.pdf
("Changing the script" mentioned earlier is related to this idea.)
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Part 3: Unhooking
Another way to deal with thoughts like a piece of garbage is to create more "distance" from them. In this case, you're not trying to change the thought or distract yourself from it, but just to unhook from it. When you unhook from a thought, it will have much less of an effect on you.
Thoughts can be categorized by the way they behave. Some thoughts are simply passing, while others are repetitive or habitual showing up every day, and still others can be sticky. These sticky thoughts can become fused or "hooked " for weeks, months and even years - impacting your identity and how you think about yourself.
While it is natural to become fused or hooked with your thoughts, evaluations, and memories and then behave according to these thoughts, when you learn to unhook from unhelpful thoughts, they will begin to have much less influence over your feelings and behavior. Of course, unhooking is a process rather than a specific technique and there are dozens of ways you can unhook.
When you start to view your thoughts as separate from you, you can stop taking them literally and can see them for what they really are – a string of words running through your mind. The aim of unhooking is not to get rid of unwanted thoughts; it is to see them as they are – merely thoughts and not facts.
The Unhooking strategy demonstrates that your thoughts are not you. They are simply ideas, judgments, and concepts that your mind produces daily.
Below are a number of options that you can try to help you unhook from your unhelpful thoughts.
"I'm Having the Thought That…"
The fastest and easiest way to create distance from difficult thoughts is to acknowledge when your mind is sharing thoughts with you. The next time you notice an unhelpful thought showing up, say, “I am having the thought that I should feel guilty about P&M”. Alternatively if you are experiencing an urge you can say to yourself “I notice I am having the thought that this urge is unbearable.”
The simple act of distancing yourself from thoughts will allow you to shift your attention to something more productive and helpful.
Thanks, Mind
Another method for unhooking is thanking your mind for sharing a thought or thoughts with you. This is particularly helpful when you experience more difficult or challenging thoughts, so when you notice these thoughts appearing over and over again, say “Thanks mind for telling me that I’m never going to be able to quit,” or Thank you mind for informing me that I’m a complete loser”. This small act could be the difference between believing the thought is fact and then being hooked to it, or being able to reject it as just a thought.
Silly Voices
A rather fun way to unhook from your thoughts is by using the silly voices method. The idea is to choose a voice for your thoughts that prevents you from taking the thought seriously. Some people use funny accents, or squeaky voices and others choose a childlike voice. When you have an unhelpful thought, repeat it using the silly voice of choice, and notice how quickly the thought becomes a joke.
Musical Thoughts
Another fun way to practice unhooking is to sing the thought.
Recall an unwanted thought that commonly pops into your head, for example, "I'm a piece of garbage." Now sing this thought to yourself to the tune of "Happy Birthday." You can sing it silently to yourself, especially if you're tone-deaf.
Notice what happens to the thought. Now return to the original thought. Hold it in your mind for ten seconds and make yourself totally believe it. Notice how much this thought affects you. This time take the original thought and sing it in your head to the tune of "Ma Nishtana” or another favorite tune.
Notice how you feel about this thought now.
Why It Works
Unhooking allows you to distance any unhelpful thoughts, particularly those attached to urges. When you detach yourself from unhelpful thoughts about acting out, they lose their power over you. Unhooking helps us realize that urges (and thoughts and feelings) are not something we must obey and act on and that we can choose how much attention we give them.
Today Unhooking is the central theme of ACT therapy, but it's not something new. For example see this quote in the Tanya:
והאמת היה כדבריהם אם היתה נפש אחת לבדה היא המתפללת והיא המחשבת ומהרהרת המחשבות זרות. אבל באמת לאמיתו הן שתי נפשות הנלחמו' זו עם זו במוחו של אדם כל אחת חפצה ורצונה למשול בו ולהיות המוח ממולא ממנה לבדה. וכל הרהורי תורה ויראת שמים מנפש האלהית וכל מילי דעלמא מנפש הבהמית רק שהאלהית מלובשת בה.
והוא כמשל אדם המתפלל בכוונ' ועומד לנגדו עו"ג רשע ומשיח ומדבר עמו כדי לבלבלו שזאת עצתו בודאי שלא להשיב לו מטוב ועד רע ולעשות עצמו כחרש לא ישמע ולקיים מה שכתו' אל תען כסיל באולתו פן תשוה לו גם אתה כך אל ישיב מאומה ושום טענה ומענה נגד המחשבה זרה כי המתאבק עם מנוול מתנוול ג"כ רק יעשה עצמו כלא יודע ולא שומע ההרהורי' שנפלו לו ויסירם מדעתו ויוסיף אומץ בכח כוונתו
Sounds Gr8! Where in the Tanya can I find this?
Warning: Spoiler!