My step dad makes me uncomfortable

I ran off to write this. Family is currently over at my parents for Thanksgiving.

I'm 22 now and my step dad has been apart of this family since I was 7. I've always been uneasy with him but it was because we fought so much (he had undiagnosed PTSD, TBI, and bipolar disorder til about 2 years ago).

We've been doing good for about 4 years now but I've noticed he's very creepy towards me.

He will hug me and run his hands across my sides before he puts them on my lower back. Made a joke about feeling up my boobs instead of my pregnant belly. Makes a lot of comments about how beautiful and grown I am. Once when I was nursing my daughter he came back to talk to my sister then adjusted himself. Idk if it was because he needed to or ya know..he was turned on by me

And today in front of family I went to the adult table and he went for a hug then he placed his hand on my butt. I immediately moved his hand up to my waist. Everyone looked at me even my mom and I know they were like wtf

I feel sick like I'm going to throw up. I don't even want to talk to anybody I just want to go home.

He's so weird and has so many mental issues I don't know if it's on purpose or if he means it

I'm going to message my mom about it tonight. I don't want to be around people upset and if I do it in purpose I'm scared he will cause a scene. I'm so confused and just want to go home :( Sorry if this is all over the place I just need to talk to somebody even if it's strangers on the internet