she cheated on me more that once

I have a gf that i've been with for almost 2 years now and it's been kind of rough since the begining because of our schedules and couldnt really see each other. Then we moved in together to be closer and so we could see each other more ofte. Well before we moved in together we had broken up. My life was falling apart, i lost my family and friends. I felt so alone. So her being my fiance i thought would be there for me. I needed her more than anything at that time but she wasn't. She said i was suffocating her and that she needed a break. I broke it off. I didnt want to but i really had no other choice. i find out that shes with someone new a few days later. I called her and wanted to talk about everything that had happened between us, but she just ended up rubbing her new person in my face. It hurt so much... I had lost everything at that moment. Awhile later i was doing ok till we saw each other. THen got back together i know stupid! we moved in together afterwards and after a few months, she cheats, lies to me, and rubs that person in my face aswell, saying she couldnt handle our arguing. She kept saying it was too much. I'm honestly disgusted I gave her my everything and she took it for granted and now i dont know what to do. My advice is this, no matter how much it hurts, what doenst kill yo makes you stronger. and that is very true. It's so hard to let a person go but it's time.