I’m freaking out for no apparent reason (in my opinion.)

I’m usually a very calm type of gal who has had some issues lately with my Former Step father and I really don’t enjoy his company yet he lives in the same house as I do. He usually doesn’t cause too much trouble but I do have some emotional response when i am around him since I got “trained” to no step up to him and when I do I get nervous and I start to shake. I talked to my mother about some of the issues telling her how it’s really not good for me and how I have some emotional trauma due to some emotional abuse (enough that I don’t really express or feel many feeling as well as saying ‘ok’ to things I don’t truly agree with.) He also constantly lies and tells people I am a lier and that I am selfish. At the same point I kind of feel bad for him since he has been a bit better the past two months and he can be nice with only some freak outs (when he did this one of the times someone who was present even asked me if this disrespect is normal and if I was ok.) Also no one in the place we live at likes him yet he will stay no matter what. My best friend hates him very much yet my former stepfather still tries to be around him as well as saying “he doesn’t like me because he is projecting and I did nothing wrong.”

I’m going to now talk to my current stepfather and my mother about this and I’m hoping we can all talk to him about it.

How can I calm myself?