thoughts:

it sounded like your response (shaving your legs, etc) stung him. if he had no feelings for you, i would think he'd laugh and joke about it instead of it leading to him telling you that you're selfish - it sounds like it opened up some sort of small wound. just guessing/talking here. and possibly over analyzing. you know better than anyone if he was trying to hurt you, or attempting to talk something out that bothers him.

as far as the occasional flakiness goes, we aren't perfect. most friends accept that you can't always follow through with something you commit to because of mood changes or depression or whatever you want to call it or label it as, because they love you anyway. that said, others will not understand why you flake out and it is usually due to a perception that you don't want to hang out with them, but if you explain that it isn't THEM and they still don't understand, then they have to deal with that as they see fit. if it's something you want to change for yourself (following up on all commitments you make) then you can try, but nobody's perfect and it's part of who you currently are. again, doesn't mean you can't try to change that about yourself if you want to.