Severe anxiety

I find it hard to remember much from my days anymore. Sometimes feel like i’m always in fight or flight. It’s been getting better after leaving a previous mentally and verbally abuse relationship but i still struggle with some things especially in my new relationship. I always feel a sense of guilt as if im doing something wrong or have done something wrong for example i worry i somehow cheated and dont know, even tho i never have or have even wanted to. i think this comes from constantly being accused and manipulated into thinking i did something bad in my previous relationship so he could have reason to bully me. How do i overcome constantly feeling guilt and worry? Even if i see someone on the street who looks familiar (probably seen them in my job or something) I’ll think i did something awful. It’s completely unrealistic and my friends always reassure me but it just doesn’t help. Unfortunately this isn’t the only thing i struggle with it changes most week, my brain always needs to be anxious. but it’s what im struggling with at the moment and it’s really brining me down