That’s the proverbial lighting yourself on fire to keep someone else warm. It’s not an effective long term strategy because you are valuable as a person in and of herself. Take that feeling that you need to do more and turn it into something actionable or join in somewhere ongoing, but don’t feel like you’re falling short unless you’re giving everything.

This is a side bit, but utilitarianism is a common ethical framework and is probably the default one in the west. If you follow it, yeah the conlusion is inevitably we should donate all our time and our money and even our organs in order to maximize “good” - which is absurd and the point of the absurdity is that our ethics isn’t complete by just saying “go and maximize the well being of everyone.” Don’t go and burn yourself out, go and be a resilient and sustainable force of justice and right the wrong you can right.