Taking care of others can be done with two very different motivations. With one, we care for others in an unhealthy way, seemingly sacrificing ourselves, but really acting out of fear or attachment.
People who are attached to praise, reputation, relationships, and as forth and who fear losing these may seemingly neglect their own needs to take care of others. But in fact they are protecting themselves in an unproductive way. Their care comes not from genuine love, but from a self-centered attempt to be happy that is actually making them more unhappy.
~ A quote from Buddhism for Beginners, by Thubten Chodron