I met my boyfriend 4 months ago and we have been dating exclusively since that time. We spend nearly every night together and overall get along well. 2 months into our relationship I figured out that he had broken up with his girlfriend of nearly 3 years about 2 weeks before we met. She was terrible to him, cheated on him constantly and he eventually had enough. Essentially, I realized I was a rebound.
He tells me he cares about me very much, considers our relationship to be serious, but is “hesitant in his feelings for me.” He said it is frustrating because I am the best woman he has ever been with. The question I struggle with is: Do I stay with him and nurture his feelings of trust and hopefully, eventually, love? Or does he clearly need to be single in order to sort out his feelings for his ex? I don’t know what the right thing to do is.
LemonVibe 
Well, I mean, just because he had just gotten out of a relationship doesnt necessarily mean you are a rebound. It is a red flag sure, but if hes not showing any other red flags theres no reason to freak out. The important thing is whether or not youre happy with him. Are you ok with just his trust, waiting on love that may or may not come? If the answer is no then perhaps you need to tell him you need space and he needs to be single for a while. If you were with him two whole months before finding out that much about his ex Id assume he doesnt talk about her much? That could be a good sign.
I know I was a sort of rebound for the guy I had been dealing with. His ex has been gone for over a year and treated him VERY badly but he still mentioned her a lot (sometimes with resentment, sometimes with fondness). He was extremely needy and easily fell into relationship routines even though we agreed not to actually date. He had problems with attachment, It had to be on his terms and even then he may never actually admit to anything. After a few months of listening to his stories about her I realized I shared an alarming amount in common with his ex. We even look vaguely alike. I think that was when I realized he was just looking for something he couldnt get back…. through me. I was the very definition of a rebound and Ive since distanced myself
If you dont feel like youre constantly in comparison or like hes making assumptions about you based on how his ex was you might be fine. If you dont feel like he just needs this relationship to keep himself busy adn keep his mind off of her, if you feel like he genuinely interested in who you are you may not be as much of a rebound as you think. But trust your gut. If your gut is telling you to leave there is probably a good reason for that.