How to control anger around a certain girl?

I'm 22 years old and was in a relationship for nearly 4 years with someone named Matthew. A year in I found out he was having an affair with his sister Jenny's best friend, a girl he also worked with. I was completely heart broken, but so weak mentally because he was abusive during the relationship, that although I knew, I still didn't leave (I know, I know, MUG) ... Basically his sister is quite odd and this girl he cheated with (Charlotte) was her only friend, so the family banned me from making this affair known to Jenny, so she could keep this friendship going, because she mentally needed to. For 3 further years I had to socialise with Charlotte - Family meals, holidays, trips, birthdays and pretend like I didn't know. It made me really ill to the point where I became annorexic, got colitus through throwing up through nerves and had blistered my stomach, and got given an external heart monitor because my heart rate was 3 times as fast due to stress, plus obviously, the obvious I was severely depressed with anxiety issues. Their affair lasted a good year, and I finally left 3 years later when I found out he'd been involved with her again. No matter how weak and friendless I was, I couldn't carry on making myself this sick. I should of left straight away but was young %26amp; nieve.



Anyway 2 weeks ago I slept with someone new called Jack, I really liked him, we've been texting and so fourth and met up once for a drink... I KNOW I can't assume a 1 night stand will develop into something so when I saw him kissing someone this weekend, I wasn't hurt at all, until the girl turned round %26amp; it was Charlotte!!!



She's remained away from me for 18 months since mine %26amp; Matthews split, but last week split with her current boyfriend, so is now out socialising. I see from her Facebook she's out this Friday in the same place I've arranged to meet friends. I even saw her at the petrol station yesterday. Should I suggest a quiet chat with her because I feel like there's still so much I need to know so I can close this chapter? Or should I just be a complete thug and slap her in the face lol. I know that's immature, but she was my friend and betrayed me and left me in my relationship to rot. She even gave Matthew an STI. I don't know if I'm going to be able to control myself, when I see her I get hot %26amp; shake and literally want to beat her unconcious.



Any suggestions on how to go about this sitation? I don't think I can ignore her, ESPECIALLY if she's chatting up Jack all night. I need to know what the right thing is to do?How to control anger around a certain girl?
control your mind.