I am extreamly sorry for this late reply. Okay, so again you are doing the same thing as you said in the very first line of your latest comment , that is, assuming things up. Assuming that he doesn't care for you, assuming that he isn't interested in you, assuming that he doesn't love you just because he is not behaving the way you are expecting him to. Dear, understand, he is not God that he will come to know about your feelings for him through some supernatural powers. Before this, he has told you about his feeling for you to which you did reciprocate but later you guys called off the whole thing. Later you felt this emptiness for him and your heart answered to it by telling you that you are actually in love with him.
But, how can you expect him to know your feelings for him without you telling him ?? He is perhaps assuming that you have stopped feeling for him. You proposed him initially but later you called off, so he is actually compelled to think that you don't feel anything for him. Until and unless you tell him that yes, you love him , he will never come to know whats in your heart and he will try to behave as a good friend with you because that is what you actually want him to do. Are you getting what I am saying ??
Again, remember, neither you nor he will ever forget your first love. First love is always a very beautiful experience even if it doesn't works out and it takes years for people to forget this beautiful experience. So, if you think that he will forget his first love that quick and move on, you are actually mistaken. What Nazneen said above is quiet justified. Though his ex-girlfriend was his first love but you have created a special place in his heart for yourself. The big thing is not in being someone's first love, it is in being someone's last love and you both could be for each other.
See, I am not forcing you to get into a relationship with him but all I want to say is, tell him about his feelings for you so that he also stops behaving like a friend to you. If after proposing him again, you feel that things are not working out, you can quit with this relationship anytime. But, just because you don't know what life has in store for you, you got to take some risk here. Things can be really beautiful but they will not be ugly, I promise.
Still if you are unsure, you can take your time and decide onto things. I know you are mature enough to take a wise decision.