Hello Lagartija: Thank you for bringing your concern here to PC. I see this is your first post. So... welcome to Psych Central.

I'm sorry you are experiencing all of this difficulty. One thing in particular you mentioned that I can relate to is having mistakes you made replay over-&-over again in your head. Unfortunately I don't know as there is a lot I can offer with regard to the problems you discussed in your post. I know you mentioned you saw a psychologist about 4 years ago & felt you just ended up going in circles. But if you could find a mental health therapist you feel comfortable with, & have confidence in, working with that person may be of help. It is certainly true that the therapy process can sometimes be both lengthy & frustrating. There are alternatives to individual therapy though too, such as CBT & DBT as well as others.

I'm an older person myself. And in my own case, I've come to the point where I have to simply strive to accept myself just as I am. Most of my mistakes (& there were some whoppers) are well in the past now. There's nothing I can do about any of them. So I just try to accept that I was the person I was & leave it at that. The primary practice I rely on is what is referred to as "compassionate abiding". It's a technique I first learned reading the books of the Buddhist nun Pema Chödrön. However here's a mental-health-oriented description of the practice:

Relieve Distress By Allowing It: Compassionate Abiding 101 | Mindset: Perspective Is Everything

I hope you find PC to be of benefit.