Need to get this off my chest.

Hello.I'm a 19 years old male, who's bisexual.The thing is, I'm starting to feel awful in the last 3 days. It was since the moment, when the guy I was interested in, told me that he would not date me cause I'm too naive.I met him in autumn, we were chatting with each other every day. We met every once in a while, but I was in a relationship back then, so we both knew that nothing can happen between us, but we still liked each other (I liked him too, I told him that, but I also said that I won't do anything with him while I'm in a relationship as I'm loyal).We stopped talking at around october, and started talking again like 3 weeks ago. We are still chatting like we used to, but when I asked him if he still likes me, he said "Physically I really do, but you're too naive for me".Honestly, I can agree with him on that, but lately I've been trying to stop being naive.I asked him if it's that much of an issue, that I know that it's a bad thing and that I'm trying to get that out of me, but he said "I've been in a relationship with a similar guy, I don't want to get hurt again"I didn't like the fact that he compared me to some guy that hurt his heart, but I can honestly say that I would do my best not to hurt him, as he's pretty much the guy I've always been looking for. He has EVERYTHING I ever wanted in a guy.I was also pretty clingy to him the past week, and I think it's getting annoying, so I decided to leave him alone for a week or two.After getting rejected by people, I've started to accept the fact that It's my personality that is pushing everyone off (I'm too caring, as they said), so I decided to be more of the cold type, maybe that way they would like me... Sad, but that's the world nowadays.How should I tell him that I don't want to hurt him and that I don't like me being naive either, and that I am more than willing to change, since it would be good for both of us?Please share me your thoughts while you were reading this. Thank you..