I realize I'm returning late to this conversation between two other people - though I am learning that Hubski operates like this, the concept of "necro-posting" isn't an issue. Which I am thankful for. But reading your comment got me thinking.
The trick is to figure out how to give without giving everything.
Is exactly why I stopped my Psych studies at the standard Bachelors level. I was acutely aware I wouldn't be able to not give everything. I'd never be able to avoid bringing my work home with me. It would eventually consume me. My plan was to focus on Child Psychology and do what I could to help young people in awful situations - my parents, bless them, warned me I was a very sensitive individual who would/could connect with anyone and everything, and that this could be used or abused in equal measure by my future profession.
In the end I decided they were right - I wouldn't have found the off switch without some serious work and part of what drove me in that direction was not having the switch in the first place.
Not that I've given up wanting to help people, I just now operate within the realms I can handle. Took a while to figure that out though.