Lost love =[

Quite frankly, you are the one who made the choice to end the relationship - showed him that it had to be over. Regardless of the reasoning, he learned to accept your decision (a feat that many ex's fail to achieve very quickly). At the same time, he does have an emotional neediness right now as he is still dealing with the loss of his mother. What your breaking up did, was show him that he cannot place his full trust in your support in times of need, so, he has gone elsewhere seeking that support.

You can definitely try to talk to him, and do your best to show him that you can be there for him as a friend if not a gf, but that is all you can do. If it turns out that he just doesn't want you at all, then it would be to your and his benefit to let go completely.