I ran away from home at 18. My mom was abusive. She forced me to drop out of school because she claimed she couldn't afford to keep me going. I worked like a dog for the next 5 years to keep a roof over my head and my sister's. Eventually it caught up with me and I got diagnosed with a neurological condition that causes widespread pain. I have to walk with a cane now. I'm 23

I've just escaped an abusive relationship and I now live in my own flat. I receive benefits for my illness. I'm taking a part-time course to complete my GED. Hopefully after that I can go to university 

But I can barely sleep because I feel so guilty. I feel like I should be doing the course faster. But my illness is currently so bad that I can barely do the hours I've already signed up for. I don't know what I'm looking for here. Maybe some reassurance? I don't know. I feel lazy and useless and I don't know what to do. I don't want to overload myself and fail this course by taking on more than I can handle. But I feel so worthless because I can't do it quicker. Does anybody else feel like this?