Write very day is good advice for some. Write often is good advice for almost all writers. They are not the same. And health trumps it all.

Don't feel guilty -- if it's your health keeping you from things, this is what is known as a Good and Sensible Reason, not a piddling excuse.

That evil inner voice is the worst, because it turns a thing you should be looking forward to and loving, even when it's hard (or hard to get time for), into a thing that is a chore at all times.