One way to look at it: if you don't feel up to concentrating on study, that probably means you're not up to concentrating on playing well.

Good to hear you're getting it done generally though.

Dont discount the value of just taking a few days or a week off and ignoring anything poker related. Just refresh yourself. When you're sick could be the perfect time. Read some books, watch some movies, and once you feel up to it return with a vengeance.