Sounds like that is just your personality. I, too, like to keep busy. I am not the type who can sit and do nothing.
I guess I am no help! Sorry.
You certainly shouldn't feel guilty for doing things for yourself, though. Take a walk, soak in the tub, make a cake and eat the whole thing! (not really), read a book. Challenge yourself to do something for yourself just 5 minutes each day. It will get easier. You are worth it. :)