Is there something about "nice guys" that make them a target for people mental junk?

The answer, quite simply, is to calm down and not take things so personally. I know that's also hard to do, I'm in a similar situation myself right now, but I've resolved to think that in the end, all that matters is that you've done everything you can to help YOUR FRIENDS. Friends, questioner, friends. Learn to be selfish (within reason) as sometimes you need that to survive. Take a little "you day" every once in awhile. If someone wants to talk RIGHT NOW, learn to let them wait a couple days if you have an engagement you'd rather deal with or you're just tired or whatever. I'm not saying turn around your "nice-guy" lifestyle, but if you really don't see the rewards in that, perhaps you should. If you're truly doing this for selfless reasons than you should be able to take a dive for people every once in awhile, just learn to take a breather every now and then. And you can't ignore them, ignoring them would be to turn on everything you stand for and I think you realize that. But you need to learn to be more ertive. Say what you feel every once in awhile. Don't just vent to a random guy on Yahoo, vent on THEM once in awhile. Out of guilt or true compion, they'll know its on them to listen to your problems too.