I think your mother is laying on the guilt because she is afraid. She is sick. She is probably afraid to be alone. Instead of facing her fear and figuring out how to manage without you, she is holding onto you much too tight. She is thinking in extremes. To her, you either go or stay. From my point of view, there is plenty of room in the middle for other solutions. If she is so ill that she really can’t be left alone, talk to her doctor about what kind of services your family may be eligible for. It may be that you qualify for visiting nurse help. Let extended family know that you need a break. If she has old friends, put the word out that you would appreciate it if folks would come spend some time with her so you can go to class. If you belong to a church or synagogue, see if there is support available there.
As for your personal issues: The first thing to do is to stop living in your fears and thinking in extremes like your mom. There’s nothing in your way of making a good life for yourself except your tendency to see things as all or none. You don’t have to know what to major in to go to college. People go to college to figure out what to major in. You don’t have “only” a few loyal friends. You have a few loyal friends! Many people would give anything to have that. You don’t have to go away to college to start college. If your mother really does need you, you can start by going to a local school. You live in a city that has many wonderful colleges and universities only a subway ride away. If you don’t have the money for a full course load, start with a couple of classes and talk to the folks at the financial aid office. Finally, it makes sense you don’t have a boyfriend. Romance doesn’t generally happen to people who stay stuck. You need to get out of your apartment and to where the boys are — like to that college you are going to. Good intentions aren’t going to change your life. Action is. Take a deep breath and go around those roadblocks. It won’t be easy but you can do it.
I wish you well.