I've had this problem in many contexts. Some of it stems from childhood circumstances, but it's also that I often read people better than they seemingly know themselves, i.e., noticing anger that they don't think they have. This can cause a lot of stress.
However, you do have to learn how to avoid taking on other people's emotional burdens.
I used to always try to please others. My dysfunctional family liked it that way. It made their life easier. That was one of the last quirks to go. It was only after being forced into being assertive to defend my kids, I've realized that it is ok to stand up for yourself. Life's been much better since, surprisingly, most people appreciate assertiveness. And being assertive is not nearly as exhausting as being nice.
It was a long journey, started with therapy 25 years ago.
When I first meet people Im more than happy to share, give of myself, etc. Usually I will either feel that gestures are not reciprocated, or taken for granted, so I pull back. Ive wondered if I feel like Im expecting too much of my generosity and I think Ive been guilty of that before. At this point though I think I have reflected enough and changed to where this is not the case.
Long term- I feel like being social requires me to "be on" which is exhausting to me. I would rather only see people when I can be decent company so I end up seeing people much less than more socially adept folks...