I am seeing this guy that i really like and care about. A few days ago I saw some texts from this girl he was flirting with and telling her he loves her and how they want to be together forever. He said I shouldn't have looked. We decided to stay together and make it work. Should I give up...or in some cases should you try to make it work?
Sounds like you have a problem with that relationship to me. Sure he's going to say you shouldn't have looked, because you caught him doing something he should have been doing ... telling another woman he loves her and wants to be with her! Yeah, maybe you shouldn't have been snooping on his phone, but then again, he shouldn't have been doing what he was doing either.
Are you kidding me? Have you lost your mind? What does it take to make you see that he really doesn't care. This guy is playing you. How many red flags and flashing red lights do there have to be? Walk away and don't look back, and find some help. You need to think more of yourself than to even consider having a relationship with someone who is telling another girl he loves them.