Being needed by someone is heavy and good at the same time.

Being counted on puts real weight on you, and that weight is also evidence that you matter in a particular place to particular people. The two do not cancel out. Tiredness from caring for someone is not proof that you resent them, and being glad you are needed does not mean the load is light.

Name what you are carrying for somebody, even just to yourself, and name what it gives you back. If it is more than you can hold, say so early to one person who could help, rather than waiting until you are empty.