Why Is He Acting This Way? Does He Still Wanna Be With Me?

He must be possessive by nature due to which he cannot imagine sharing his things and asks you off and on whom you text or talk to. You need to realize that he is not happy by your success in life and school and talks short on phones. Here you need to decide that after breaking up you want him in your life or not rather than thinking he wants you or not.

It's not so much that he still wants to be with you, but in any relationship that has ended, even if it was on good terms, there will still be harsh feelings for a while.  It sounds like he is upset on how easily you got your life back on track, and were able to move on from the relationship.  People are funny in this way, while most of the time they want to see others succeed in life, when it comes to someone doing better than they, themselves are doing, a mixture of feelings can come up.  This could be what is causing him to act this way.  Or it could just be that he was so used to being in a relationship with you that he is not quite ready to see you talking and hanging out with other guys.  It may take time but he will get over it, and hopefully he will stop asking this way.  But if i were you i wouldn't get it into my head that he wants to be back together.  Like you said you two had your reasons for breaking up, that is probably the way it is meant to be.