Do I feel bad? Yeah, definitely. I think the majority of people on the planet are entitled to an existence better than what I, a white lower-middle class American, enjoy. Except, of course, for murderers, rapists, etc.
Do I do anything about it? No. I don't trust charities, mostly because I don't have a solid bit of feedback saying, "Your $X did this!" And I don't know which ones are reputable. As for going to Africa and helping them...no. Sorry, but no. I have a strong desire to not die of AIDS. And since 69% of AIDS patients reside there, I'm not going. Plus, there are myriad other diseases I could catch out there, most of them fatal, and if not fatal, then debilitating. I can't do much good dead or crippled, now can I?