Best thing to do is to not talk to him at all. You can't miss what is right in front of you. Besides, if he knows you are obsessed and still want him then he has no reason to stop what he is doing. He knows when he is good and ready to come home (if he decides to) then he can. You will be there with open arms. Let him think you have moved on and that may get him thinking.
Work on yourself and become an independent woman. This way he will see you out there doing things for yourself. He will notice that you aren't clingy and depressed and that you have moved forward. You are divorced and that part of your life is over. If you have a chance to win him back, you have to prove to him that you have changed. But before you can do that, you have to prove to YOURSELF that YOU have changed.
Each and every person on here has given you advice and I would like to see you use it. Stop dwelling on the past. Stop dwelling on what your xh is doing. Stop dwelling on if he is going to help your son buy things. Stop worrying if he is going to call you. Actually, if he does...don't answer. He knows you want to talk to him and if you don't then he will start to wonder what you are doing.
Turn yourself around and become a different person than he left behind. I know you have it in you. Everyone knows you can do this or they wouldn't come back here day after day to try and help you. It is time for Sunshine to take control and become the great woman that she is.
Don't lose the person you are inside because of this. You are stronger than you think. Take some of that strength and put it to use.