I have not gone 18 days (streak) clean since I figured out about how my body works (lets say 18 years). On the one hand, I am very proud of myself for cumulatively going 21 of the last 23 days clean, but this all puts into perspective the idea: "the higher the step, the bigger the fall". Countering how proud of myself I was after the 18 clean days was the shame and difficulty I felt while recovering after what was (at least to me) a nice accomplishment. 

I am scared that if I ever make a larger accomplishment (be'h), when I fall (chas v'shalom), the feeling will be worse. If I actually ever accomplish 90 days and then fall, that will one hell of a fall - would I ever recover from such a fall. The anxiety of that thought - falling after 90 days - has me paralyzed to try harder. 

My entire Jewish worldview and "performance" (wrongfully so, perhaps) circulates on how good I am at staying clean. When I am clean, I wake up for shacharit, learn torah and feel great. When I fall, I skip shul, and play psychological games with myself to justify the behavior and also to prevent me from completely melting down.

Experienced comments welcomed, and חורף בריא

I've been in that yo-yo that you describe many a time.  I mean to say that when I am "clean" or "good", everything is fine, and I set all these religious "goals" for myself.  When I have a fall, I find it difficult to stop right away and drop off my religious observance, plunge myself further into addiction until my conscience gets the better of me, and I come back.  

For myself, I find that reading Jewish psychology books -- like from Rabbi Twerski, really help in breaking that cycle, which I believe to be "self-pity" because I "failed".  I often don't feel like praying at that point, and it becomes like a compromise: "Well, what are you willing to do?"  I can usually at least read a spiritual book.  

I think reading those types of Orthodox and compassionate material helps to form good and holistic Yiddishkeit.  

Sorry, this is the better answer:

guardyoureyes.com/articles/questions-and-answers/item/scared-of-falling?category_id=36

Now I am b"h 198 days clean, but when I started I fell a few times , and one of them was long after 90 days, it was at day 134, and to say the least I felt horrible about myself and did not know what to with myself, I was sure that its all over, but let me tell you, #1 yes we are all human and we might/can fall, therefore we should always be on hi alert,  and even if we fall we can get up and continue on our journey,  #2 its Important to realize that the more day's you have behind you the more you trained yourself self control and not to give in to your cravings.  Now of course now one wants to fall and of course the more day's you got behind you the worse it feels when you fall (talking from experience), but dont forget its not like you are starting again from day one, you got all that training and will power thats behind you.
so my friend,  keep strong and try your best, keep on posting we are looking out for your success!

Welcome. It should be with hatzlocha. Do not define yourself or your value based on this one issue. Yes it is very important, but it is not the entire yiddishkeit. Step one, be proud of yourself that you are reaching out for help. Hashem has great Simcha from that. Secondly, every little bit counts. If you stay clean for one extra day, you have great zchusim, plus you are training yourself that you can iyh be in control. Stay in touch.

There are many who have done it, who have kept clean for years. I think there is no reason why you cannot make it to 90 days, 900 days and beyond. Like many on GYE says, fighting the addiction is a one-day-at-a-time process, we must have the courage to keep going, stay clean for each and every day, no matter how many days we have been clean before, or else there will be no way to reach 90 days, and reaching 90 days and beyond is entirely possible, as many have done it. Hashem knows we are trying. It is almost impossible to be clean ever after with just 1 try or even a few tries, but what is important is that we always try and carry on despite our fears. We can stay clean for longer and longer and I'm sure Hashem will have naches for us.