My mother engages in attention seeking behavior. Any advice?

My mother lives independently and is 90 years old. She needs outside help but refuses to accept it from anyone but me. I live an hour away which means that any trip for any purpose involves at least two hours on the road. She lives near a major metropolitan area which means traffic congestion and accidents on a regular basis. I work full time and would like to spend some of my free time with my husband and children. I call my mother every day and sometimes a couple times a day. I visit her weekly and do her grocery shopping, household chores, bills and take her to doctors. She visits me at least six times a year and stays for 5-7 days each time. She has been an anxious and obsessive person her whole life. She is very demanding and controlling and wants everything her own way. Until my father died she had him to boss around. Now its me. So she will constantly buy and return things, complain about trivial things in her house, complain about minor health issues, etc. Most of the time I try to redirect her or solve the problem for her. But I have finally realized she doesn't really want the problem solved. She wants to manipulate me into spending my time with her. I realize she is lonely but she has refused every attempt that I've made to get her out and about with others. She even refuses lunch outings with my aunts and cousins. She says she only wants to be with me. I'm really burned out. REALLY REALLY burned out. I have been putting up with this for 9 years now. I've come to the end of my rope.