My [m28] girlfriend's [f27] jealousy is ruining our relationship and she resents me because of my past.

I love my girlfriend of 2 years but lately we've been having a major issue. Lately she's been incredibly jealous, of a bunch of girls but of one friend in particular to the point of tantrums.

I have one friend who when we first met over 5 years ago, we hooked up once when we first met. Both of us didn't feel anything, decided to just be friends and have just been platonic friends for years. My girlfriend asked me about any friends, and I was honest with her and told her that. She hates her and is so resentful towards me now.

I don't hang out with this girl one on one, only in group settings and not often, and even then i try to keep my distance because I know it bothers my girlfriend. But lately she's been getting more and more jealous essentially guilt tripping me for hanging out with my friends at any event she happens to be at.

When I try to talk to my girlfriend about it, she just stonewalls me, crying, telling me she's fine and being all passive aggressive. I tell her I'm trying to work with her, invite her along to every event, but she tells me she doesn't want to be there.

I don't know what to do. If I try to talk to her about it she just gets upset and refuses to talk to me, storming off or stonewalling me. She gets angry at me for trying to talk about it, tells me she's fine as she's crying. She's convinced the friend flirts with me although says I don't flirt back. I told her I don't think she does and treats me like any other friend (besides, I have set her up with other friends of mine... there's seriously no interest there at) but I offered to talk to the friend and tell her to cut out the stuff my girlfriend is bothered by, but then she threatens to breakup with me if I do. She tells me to go hang out with my group of friends but then gets upset when I do.

I feel like she completely resents me for my past, bringing up exes I don't even talk to at all, or anything, and she does get jealous easily. She'll resent me for ever dating certain ex-gfs, saying how she doesn't see what i could have possibly saw in them.

She has had a rough past, but she assures me I never did anything to break her trust (i don't flirt with other girls, am always loyal to my relationship, etc) yet she still gets upset. I don't know what to do short of cutting off all of my friends. That seems unreasonable to me.

What do I do? I don't want to break up, but this jealousy is tearing us apart. Any time I try to talk to her it's in vain since she refuses to talk to me about it and just gets resentful and avoidant. How can I save my relationship?

Tldr: I'm afraid my girlfriend's jealousy is going to be the end of us. I feel like I can't hang out with my group of friends without her resenting me. Do I cut out my friends? I rather not breakup.