Blushing

For as long as I can remember, I have blushed quite a bit. I've gotten better as I've gotten older, but I have a really annoying problem. I can't comment in class without blushing! This was never a problem before I was in college. But, I've been here over 4 years and I still can't do it. I'm not an incessant commenter/question answerer. When I do make a comment, it's pertinent and intelligent. But, that doesn't matter. I blush! And then, I realize I'm blushing and that embarrasses me so much that Iblush even more. What the heck?