everything

Everything I do makes me hate myself. I feel like I can't speak reasonably to myself anymore. If I'm aware of this, I know I should be abler to fix it. I'm just finding it really difficult to take a step back and breathe and let myself just be instead of needing perfection from myself...
I know its not realistic. I know a lot of the things that bother me are pointless and no one else thinks about them. I don't know how to let things go and it hurts. I'm hurting. 
For instance, I once speculated with my therapist, trying to figure out why I have such a hard time with memory. I don't know if it had to do with medication, or anxiety, or just bring generally so inwardly focused that I can't form full memories? But I wanted to know. I wanted to understand what's going on in my brain and basically he didn't know either and he said "I don't think that's it" but it has stuck in my mind , months later, and I feel incredibly stupid and I still kick myself for not understanding, not being smart enough, not knowing what  is happening around me. He wasn't even being nasty and I knows that but it is the fact that I AM stupid. 
I don't know how to slow down my thoughts anymore and I'm feeling so overwhelmed. I have constant negative self talk that feels like its bombarding me ... I feel like I'm tearing myself down and I can't control it.