Jealousy (help please)

Does anybody here have any issues with jealousy or just feeling maybe paranoid sometimes? I literally can’t stand my sister in law. She is such an attention whore. She loves to post about her entire day every day, she post pictures where she’s half naked but she’ll have to focus on something else as if nobody notices. She is an entitled bitch and looks down on everyone and thinks she is superior hot shit or something. She is always coming up here (we live behind them) making up bull shit to talk to my SO, to where it feels like she’s doing it on purpose. She has cheated on my brother before so I know she doesn’t care to look and go after other men. I feel so uncomfortable every time she is around. She bends over all the time to just pick up random shit but makes sure her ass is facing you and will pull her shirt up some so her ass isn’t covered. She literally weedwhacks in a bikini. They don’t even own a pool but she’ll do weird shit in her bikini. Sometimes when it’s cold so it’s not always a temp thing.

Okay I’ve ranted too much. I just hate her and it’s getting where I am hurting myself mentally thinking about it when she comes up here.

I just need advice.

Also want to note, I have a wonderful relationship, I don’t have anymore reason to believe he would ever hurt me, besides my natural worry.

Ive always had some type of jealousy issue, my first relationship was very toxic and some habits die hard.

My last relationship was with the sweetest and the last guy on earth to cheat. But I still found myself paranoid and now see that as a huge red flag( obviously)

I have been cheated on in very gaslighting ways, he once grabbed a girls butt while he had his arm around me and told me for years it never happened even when I was very very sure I seen it.