Your view on doing charity work is off. To not help others because the system that created the need should to be changed is foolish. It is not living in the present. Besides, revolution changes nothing but the characters.
You do not feed a hungry person because you want to end world hunger, but because he is hungry now. There is no end to the projects you can do.
Several year ago I got a grant to build sukkahs for people who never had one before. (Chico went from 2 sukkahs to 8. Earthshaking? No. but a nice difference) I bake and distribute challahs free to people on Shabbat. (One person told me they were just going to have dinner, but because they received the Challah they set the table, lit the candles and had a family Shabbat dinner.) My project to make and distribute tsitsit is taking off. A number of people now wear tsisit, a reminder to be a good person and to consider your actions.
Small steps on a small scale. Not as big as feeding people, but at least it may be feeding hungry souls. Or maybe not, but it is what I can do. The talmud says if you save a life, you save the world. That's big.