Ex boyfriend won't let go!

My ex boyfriend broke up with me...I wanted to get back together, and he claimed to want to also. But he thought it was for the best. Any way I've kinda just let him do his own thing, I said I wouldn't be friends with him, because it would be too difficult. But he won't let go...he still texts me and he still makes it clear he's feelings for me. He randomly emailed me out of the blue yesterday saying "I do still love you"

I have asked what his intentions were and he didn't really have an answer. I said is it because you want to get back together? He said you know I do want to get back together, but I don't think our relationship would survive. Why can't he just let it go? Every time I feel like I'm getting somewhere, he messages me again