I think I'm losing feelings.. finally

Me and my girlfriend have been together for almost 2 years but they haven't been the best. She cheated and lied a lot and so many people told me to break things off with her, but I just couldn't cause I love her. I found out she cheated on me again about a month ago and I haven't felt the same since. She went out with some "co workers" but one of them is a girl she said she liked. And the other two were a couple she works with. She said she was going to hook up her friend with her but she didn't mention her friend was going until I said something. She's been known to lie before. And I guess I'm not as upset as would've been before but I don't know if it's just me or am I just losing feelings for her.