I know you think you're trying to figure him out, but you're not doing it in a fair way. You have got to stop being so black and white in your thinking.
"Either he likes me or he's using me..." Where'd you get the idea those were the options? Sounds pretty random on your part, to me.
- He could like you.
- He could be using you. (your two options)
- He could like you AND be using you.
- He could like you and have a lot of other things going on, meaning you are less of a priority, but he still likes you.
- He could have a lot going on and is trying to DECIDE if he likes you enough to adjust other priorities.
- He could be fine and you are misrepresenting the facts, no way for us to know.
- He could be fine and trying to get closer to you and you're totally missing all the signs for some reason.
I could go on and on here... the point is it's an awful mental exercise to put your sole persepctive on a situation and implicitly declare your view as the correct one... then try and solve it from there. Lose-lose in my opinion.
This can only be handled with you two dating face to face over some lengthy period. You don't even have to be confrontational about it, there is the chance things are moving along correctly and he wants the same things you do.
Also, it is a GOOD thing for a boy to have a lot going on in his life. Being well-rounded and involved should provide for more opportunities for you to know more about him and not being smothered by him. Make sure YOU have a well-rounded life, too. The boyfriends should make up a small part of a complete picture.