I don't volunteer because I'm a good person. I don't do it out of sheer altruism or so I can feel smug about all the awesome things I do to make the world a more awesome place.
I volunteer because it's the bare minimum I can do and not hate myself.
This is a judgement I would never make of anyone else: any money you give to charity, any volunteering you do, any activism to make stuff better for the next generation - that's amazing. Anything is better than nothing. And if you do nothing - that's your choice. I haven't a clue what else you've got on or what your reasons are for your level of involvement and it's absolutely none of my business.
It's a depression thing, I think: applying incredibly harsh judgements to your own behaviour that you'd never dream of applying to anyone else. So if I did any less - gave less money, spent less time volunteering, made any less effort to spread awareness and change minds - I'd hate myself. I'd berate myself for being lazy and tight-fisted and caring too much about myself and not enough about everybody else in the world. (Which is a great way to head straight for burnout, by the way - I don't recommend it.)
This is in no small part a very gendered neurosis: I am only worthy if I am helping others.
And since I've been doing all this, I don't really think that much about how rubbish I am. I mean, I still get the acute pangs of embarrassment over something idiotic I said in 2002 and give an involuntary embarrassed groan while I'm paying for my vegetables - it's not like there aren't still days when it feels like 30,000 people are chanting YOU'RE SHIT AND YOU KNOW YOU ARE in perfect harmony inside my skull. But it's been a long time since I've been crippled by the certain knowledge that I am a terrible person with no morals who has no right to speak or opine or even exist.
Which is partly because I'm just better: my depression is nowhere near as severe as it was.
But I'm certain that I'm better in no small part because I'm active. Donating and volunteering and activising are proofs I can throw in the face of my depression: solid evidence that I'm not absolutely the worst person who has ever lived. Activism as therapy.