I hit reading slumps every once in a while.
For me, I read something that doesn't take much thought. Pratchett, almost any mystery, reread of books I love.
Mostly I don't worry too much about it. I've got a lot of books on my Kindle and if something doesn't strike my fancy, I try something else and then something else and then something else until it clicks.
Reading should be fun. If you're forcing yourself to read, that ain't fun.