If he gets used to having you around anytime and anywhere, he most definitely will take you for granted.
Don't pretend to be busy, make it a reality instead. Focus on improving your personal self, and your professional life as well.
Guys love a challenge. If you ignore him and make him chase you, he will rise to the challenge if he's really into you.
If you want him to think about you, try to deviate from your previous over-eager behavior.
While you're doing your best to appear cool and unaffected, try your best to avoid looking uninterested, too.