It can sometimes take a number of years to get over a past relationship. I think you would be making a mistake to try and get back in touch with him and to try keeping in touch. He seems to have moved on, while you are not yet in another relationship that you feel deeply about. So he has the advantage. You two as a couple did not succeed, and that's not going to change. You are kind of torturing yourself.

I know when you talk about being in touch with him, it's not that you see the two of you dating again. But what do you see? Keeping in touch with old loves is not usually a wise idea. That's why people generally don't do it. I've had that feeling, myself, about wanting to kindle the embers of friendship, where there was was something more. It didn't work out well. I ended up causing more pain for the other party and for me. Sometimes you have to let things fade into the past where they belong.

Sounds like you are really trying to fill a void in your present life. This is not the way to do it. Invest in the relationships of the here and now, not the past.

It's nice that you still care about him. You probably always will. That doesn't mean you should do something about that. It's not what he wants, or he would have done something different from how he reacted. This may be keeping you from moving on to what you need relationship-wise now and in the future. Ten years is a long time to still be carrying a torch. Pay attention to the opportunities in the present, or you'll never get out of living in the past. That would be too bad. You sound like a caring person who has a lot to give to the right person. It's not him.