When we first talked about dating, she promised an honest and open relationship in the sense of communication.
In the time we’ve dated, communication hasn’t gotten any better and is absolutely terrible compared to before. I’ve gotten cheated on, she lies consistently, still talks with the men she flirts with and is still incredibly irresponsible. She also claims to have cheated on a guy simply because she didn’t screw or see him for two weeks. I won’t be able to see her for a while so I’m concerned.
She has plenty of great qualities and I am madly in love with her, but I can’t trust her to save my life. How can I resolve this? We get along great, and have awesome chemistry.
She has PTSD related issues, so I can’t approach these issues directly without her shutting down and going dead silent for two days. How can I resolve this?
LemonVibe 
You can’t help her because she hasn’t asked for help. You can’t trust her l, because she’s given no reason to. Seek therapy for yourself before you do any more trauma bonding to get out of this relationship. Its not healthy for you and she might need that kick in the pants to get help herself. One thing is for sure, you don’t need this and can’t help her. Moving on is the only healthy thing for you atm. All you can do is encourage her to seek help.