Who says that its never enough? You yourself? Then you might set a too high standard. You don't have to be mother theresa or ghandi to be a good person. Small things do matter.

I know this sounds easier than it is, because I suffer from exactly the same. Even on medication those ruminating negative thoughts are still there. But I try to be kind and helpful and see it as an antidote to the bad things I have done (and will never do again). And sometimes I am not kind, that's ok. Im just a human, so are you.