Those of us (myself included) who tend toward introversion, are good listeners, are happy to help others, and have difficulty saying no may have learned this behavior in childhood. A healthy dose of these behaviors I think makes for a happier society. But, if carried too far, can result in a person feeling depleted. You can find a good analysis of this phenomenon in the writings of Dr. Gabor Mate, particularly “The Myth of Normal.” If you have not explored his writings, you might find them helpful.