What do I do with my gf?

Okay so my gf had been talking to another dude for 3 weeks but never flirted back until me and her broke up for like a day I found out bc I confronted the dude when he called her my babe , and I talked to her and she called me crying saying she only did it to forget about me because I hang out more with girls then I give her attention , now she's been a mental mess and I confessed I cheated on her a couple times but never met up with girls just flirted . So we took a break for like a day since she can't go a day with out texting me and telling me she hates how happy I can stay after all that's happened and that she wants to spend the rest of her life with me what do I do