If he started conversations for quite a few days, then stopped and now is avoiding you, he may have been wanting to continue hooking up or see where things go. If you played it too cool you may have come off like you are the one not interested and hurt his pride/feelings first. Of course this is just me guessing. The only way to know for sure is to reach out to him and talk to him about it. If it seems you are losing the relationship anyway, what do you have to lose?