This seems to be a common ocd problem, but there is actually also a separate name for it, something like trichtotrillomania, which includes hair pulling or tweezing, i dont know much about it myself, but there are plenty of posts on here from people who pull their hair and eyebrows, it seems to be quite a common condition, so maybe check out their posts too, and im sure someone on here will be able to give you more information on it!
hope this helps a little!
Laura