how to make a boy return to his eagerness to me?

Well, I dont think he likes you that much. As you have mentioned, that he likes to get around with you in public just to show off he is populous with girls. I am assuming that he's using you.
He doesnt act the same as before? Was he more enthusiastic than now? I am kind of confused with you writing. Is he your boyfriend?
You said that he seems like he has a crash on you, but is that true? Did you misunderstand? By the way, do you like him? or maybe you should ask yourself, are you willing to be used?
If he's that bad. LEAVE HIM. Why you have to ask him for help? What about other friends?

2006-12-01 06:38:59 補充：
you are silly, girl. The reason that he uses u to show off is because he wants to SHOW OFF THAT HE CAN ATTRACK GRILS...HE IS POPULAR...HE IS GREAT~! (But you know that based on his personality he is not!)

2006-12-01 06:39:17 補充：
Like others have said...you reall should move on. Respect yourself, and you deserve better than this~! Good luck~!

2006-12-01 09:25:34 補充：
I think that he helps you on your homework, dates you, and other stuffs is his way to secure you; which means to keep you with me. He needs to attrack you. The more you are attracked to him, the most likely you will stay with him; thus effecting his purpose of showing off.

Based on what you shared in your question, it appears that you really would like to have a relationship with this person. Having said that it does not appear that you are in his radar scope, there is not eough attention, chemistry, and interest from his side for you. I would suggest you to move on.....

he may has a girlfriend already