Needing some major advice

I have been with my boyfriend for three years. He has always had to take care of his family and cousins who are older due to them being sick. He is constantly having to care for them and really doesnt have much time for anythjng else. Our plans never follow thru ever . Its just very hard i feel so bad because how his family isnt doing to good and he is expected to take care of them basically forever. Im not sure what to do i feel like he only has time for them and maybe he should just be there for them and i should just leave the picture is this selfish of me ????