“Try to never be the person who cares the most” was an offhand remark my dad made to me when I was stressed over a group project in school. It helped me what in hindsight would’ve been very stressful situation many, many times.
I think I can apply it to both my work life, thinking about times where I overworked myself at a company where nobody else cared enough, and to my personal life, thinking about times where I invested myself fully into relationships where it wasn't certain to be requited.
WSJ Oct 2021, "Burned Out? Maybe You Should Care Less About Your Job", https://archive.md/2fsRi
It feels stressful and lonely because you feel like you have to hold all the strings together and if you fail, the whole project will fail.