I have the same trouble sometimes feeling guilty for not working, and like I need to be doing something constantly. It's hard for me to just sit and relax because I feel guilty that I am not cleaning or doing work of some kind. I still struggle with this myself so I don't have any answers, but just try not to be too hard on yourself and take things one step at a time. I recently had a long to-do list. I didn't get it all done in one day or even two, but if I manage to get one or two major things done a day then eventually I get through them all, and that's okay too.