You know something? I haven't done anything for the past two days and I'm not guilty about it at all
Should you feel guilty?
I don't feel guilty about anything
That's good, because there's nothing inherently wrong with what you did.  People should be allowed to take a few days to relax every now and then!
We're made to feel we should always be doing something constructive.
True, but you'll actually accomplish less by being relentlessly busy -- you'll burn out sooner than later. You need time to breath and let your mind run free.