Feelings for ex and another guy, help?

This will probably sound immature but I'm 21. Was with my ex 2 years broke up 5 months ago as he was stressed with college but realised it was a stupid mistake and got back together within 4 weeks. Met this guy once we were back together who showed a lot of signs that he was interested in me but knew I had a bf. Me and bf broke up again 2 months ago around the time I met the guy (nothing to do with break up we had a big fight over our 1st break up and how I was still hurt because of it) I started to get feelings for the new guy so felt maybe it was best to break up if I was feeling something for someone else (ex doesn't know about him). After the break up I hinted to the new guy that I liked him and was single but he completely backed off and showed no interest anymore. I was annoyed by this because he was interested when I was taken but now not. Havent spoken to him in 2 months so I know I have no chance but everyday I think about him and wish I could be with him. I still love my ex deeply, I don't want to forget about him, we still talk and recently he has been hinting a lot about 'us' again and i think he wants to give it another go. I dont know what to do? I feel like if I get back with him I'll always wonder if the other guy would have come around once he knew I wasn't going to get back with my ex but that's wishful thinking. Any thoughts? Sorry it's long.