dating after toxic realtionship feels impossible

( tw for sh/ grooming/ suicide attemps)

I've been in a terrible relationship a few years ago, they were older than me, had lots of mental health issues. The whole relation was quite traumatizing to be fair. I was very young, and had to deal with a very unstable adult ( i had to handle they're suicide attempS, sh relapse etc) . I got cheated on, manipulated,...

This was my first and only relationship.

recently I started to feel like that I was over all of this, so i started to try to flirt/flirt back with people. However i always get the worst guilt when i try to. Every time I feel like i talk like my ex used to, as if i was acting like them. I know that it's not the case at all but i can't help the soul crushing feeling each time i interract with people i'm into (even if it's purely platonic exchange)

It's horribly disturbing and completly keeps me from engaging romantically with anyone.

I feel lost and alone as i can't find much testimony similar to mine. Any advice ?