constantly questioning myself. It's making me unhappy

[starodyssey2015]

I've done this for a while. I know it's linked with my anxiety but I can now control the attacks. But if someone is 'off' with me or not as friendly as I am I will run it over in my head for days. Even preparing myself for if it happens again. I put a comment on a post on facebook the other day about horse racing (I'm against it) and said something like I don't think it's worth all the horses dying. And somebody from school trolled me with his friends (putting picturss of dead racehorses uo) and I know he'll have thought it was funny. But I found it hurtful , with or without the pictures, and have been running it in my mind since the grand national!

When out, i'm constantly apologising for daft stuff like if I'm walking towards someone, and I move, I then say sorry. I was at an induction for my new job the other day and I apologised so much that my new boss called me up on it and told me to stop it because I hadn't done anything.

I'm just about to go into a job working with vulnerable people (drug sufferers) and I really don't want to appear weak so I need to get a settle on this. ANY advice please.