R76, You are a truly good man. And nevertheless you are mean to yourself. Please let me explain what I mean.
I think you are not mean to yourself directly - instead you have found a way to use the Torah to whip yourself with. You invented a Torah that tells you "I must recognize that I have sinned against G-d", as you put it. And you have created a G-d Who expects you to feel deeply ashamed and oh so sad about your multitude of sins and about the poorness of your service to him (you wrote, "to my shame, I pray only one amidah"). Where do you get such an idea from? G-d certainly has no desire or pleasure in your grovelling to Him. He knows you and I are just people. Fallible, weak, and small - like me and like you. G-d certainly knows that - He is not a fool! Yet here you are, chaver - you get religious, and use that religion to enable you to focus whole-hog on what you have done wrong and be ashamed!?
Thus, G-d is really the mean one.
But it is not G-d - for He is NEVER MEAN. He never was and never will be mean or bad to you or to anyone. He cannot be mean or bad any more than He can break a hip, get pneumonia, or drop dead. He wants none of your shame-talk, and no such thing is in His Torah. Rather, it is you and only you who are being mean to yourself. But you do not like to admit it so you create proxies to beat you up for you.
Ultimately, you are the one treating yourself badly.
Stop doing that! I really hope you just stop. It will take time to learn a new way. The Torah is a Torah of Joy and deveikus (relationship with G-d) as much for the one who has sinned as it is for the tzaddik. And in addition, G-d truly and completely forgives! And even before He forgives, he truly and completely loves you no matter how much sperm you have spilled on the floor or why you did it.
So from today, please start learning to live without beating yourself up and without treating yourself like garbage. You are not garbage. You are a precious human being and a sweet Jew. And Hashem's main desire is clearly to help you grow TODAY and do imperfectly best as His sweet, precious child.
This will take a little humility - for contrary to your opinion, you are a truly good man.