@geminiluv,
Be unavailable (which it sounds like you've already done a bit - good for you).
I think his excuses are mainly lame ones. He's going away for a few weeks and that makes it harder for him to at least be courteous enough to contact you if he won't be able to make his commitments? Sheesh, people go away to war for three years and are better at commitments than that.
I think he's not that into you, sorry to say. The signals all seem to point to, "I hang out with you when my other plans fall through." Sorry.