Seriously Oldspice, that's stress, I've been though exactly the same thing and actually had tests for MS because of it. (I had blurred vision too). I'm ok now though. A friend of mine who is a speech therapist says that if you're stuck for a word you should stretch your calf muscles and it's supposed to help - reflexology or something. You might feel a little self-conscious doing this in front of a class though!
