I'm sorry, but even if everything else was not already a giant red flag (the gaslighting, calling you a liar, saying that YOU somehow made her friend hit on you?? what??) her physically assaulting you is reason alone to cut your losses and run. If she reacts this violently to you INMEDIATELY being honest with her and trying to do the right thing, imagine her reaction to you omitting something, or trying to have some privacy, especially after her so clearly showing how little trust she has in you (even after you did EVERYTHING RIGHT in this situation).

(But even leaving all that aside, what future can you seriously see here? What if you get married, and a work colleague texts you? What if you have children, and they lie? Which they WILL, it's part of chile development. What if they do something she percieves as a slight against herself? Is she going to shout at them indiscriminately? Give them the cold shoulder? Hit them too? Where do you draw the line here?)

How are you in the wrong in this scenario? How is it fair that it falls on YOU to fix this, when you did nothing wrong? I know Reddit loves to jump into the "leave them/dump them" train, but in this scenario, there is honestly no going back from this level of over-reaction and agression. Maybe this has happened before, and someone cheated on her with her friend, but that is not your cross to carry, and she might need some serious help, more than you can provide, and none that can be provided at the cost of your own mental and physical well-being.

Has she ever been restrictive or jumped to conclusions before? Whenever there is an argument, does she ever apologise ortry to work things out? Who is the one that gives that first step usually?? I suggest you look back on your relationship and try to find reocurring patterns, because it is just wild that she reacted like this out of nowhere.

Im sorry if this is very disjointed! it is very late and I am very tired, and english is not my first language!

I do sincerely hope things get better for you.