Is this Selfish?

I was a very studious student. My mother made sure of this b/c she was determined that I would be the success she was deprived of becoming. My childhood was very lonely b/c I did not have any friends nor had I ever had a boyfriend. School was the only thing that mattered. In fact, I can honestly tell you that I know more about the librarians in both my h.s. and college than I do about my clmates. Now, I'm in my late 20's. I have a small circle of friends and have begun dating someone. For the first time ever, I'm actually enjoying my life. However, my mother is becoming very ill. She believes I should move back home and take care of her. I've offered to pay someone to do that but she believes that, as her daughter, it's my duty to do it. My life is so great right now, I don't want to give it up but I know I'll have to when I move in with her. Am I being selfish for wanting to live my life or should I move in with her?