I too have OCD but what you discribe sound more like a focus issue like ADD. Most of these disorders come in twos, I would check into this first. I also had ADD and my focus is bad as well. There are was around this though, it just will take a little more determination then for most. :) I am happy to say that it can be done. :)
Perhaps meditation isn't for you? While it can be done, maybe try using other things. Really the biggest advantage of it is to calm your mind, but the racing thoughts can actually be advantageous when you can embrace this and utilize them for creative purpose, rather than fighting against it.
It's often easier to merely redirect the flow of water very slightly than to halt it entirely, and ride it where you need to go.