You might be wrong about some things, and you may have done awful things that haunt you. Or you might just feel like that because that seems to be what humans naturally do, and because of the disconnect between the ideal we strive for and the reality that makes us fall short of that. But your feelings, your reactions, everything about you is valid.
When you lose your temper and do things you wouldn't do when you are more collected, you aren't a failure. The collection of patterns and things that make up you are simply set up that way. That is your reaction, and it is an invaluable, inseparable part of your experience.
I have found that if I allow myself to experience me at my worst, let my brain crawl around in all the dark places that I avoid going, then I receive the gift of all my missing pieces. The shortcomings that make me stumble are then coupled with the understanding of how to cope with stumbling - or even how to avoid altogether the situations in which I am prone to stumbling. And with that, the anxiety and other problems structured around the stumbling start to fall away.
Sometimes, it even leads to my discovering what I am very good at - the niche that I should be occupying. And if I follow that niche, I experience moments where everything suddenly pops into place. I experience what it is like to truly be me, without the noisy and horrifying distractions. It is a very good feeling to strive for.
That may not work for you. But I hope that if any of this resonates and sounds like your experience, that you find it helpful.
I wish you all the best, and I thank you for letting me share this with you.