Okay, you know how in marital arts there's both hard style and soft style. Hard style would be something like karate that meets force with force. Soft style would be something like aikido which flows with the force and redirects it. And the redirecting is more the zen approach of allowing it to happen rather than forcing it to happen.
With my own struggles with OCD, if I get to a place where it's okay to do something and okay not to do it, that's a pretty good place to be. And this only occasionally happens, and that's okay, too.
So, with the counting while you read, maybe you could think of it like grids on a map or marking your terrain. Yes, it's slowing you down, but you're trying to look at it a little bit in a humous way. And thus, kind of detoxify the idea. And not add more power to the thought, just let it be, which is also kind of a zen approach.
If this is slowing you down for school, please get a tutor if you can. Or maybe get a book on tape, or asking a person to read the most important parts into a tape recorder?