Should I feel guilty for not spending as much time with my mother?

I will start off by saying that I am an only child and I have lived with my mother by ourselves since I was a baby. I will be graduating soon, and I have not spent much time with my mom lately. I feel incredibly guilty about it, because she is 63, retired, and always home alone, so I feel like I need to be around her. Even when I am home, though we don't do much, and she mainly sits on her computer.

I have always felt guilty about anything involving my mom, like she has instilled a really strong guilty bone in me. At this point in my life I am becoming extremely independent and wanting to do my own thing. I am tired of the extreme amounts of pressure she puts on me for school, when I am already a great student. I have entered a serious relationship, which has been the largest problem. She likes my boyfriend a lot, but I am never home (mainly because we have a landlord issue and no one besides us is supposed to be on the property at the moment).. I wish she could realize that I am happy with how my life is right now, and I have my own plans I am making.

Just today I mentioned how I was going out with him again tonight and she practically had a fit saying that she is "tired of me never being home", I normally just hang my head down and take it, but this time on my boyfriend's advice I stood up to her. She did the thing she always does and says "Well fine I will start focusing on myself since you don't want a part in this with me."