I do the same thing and have OCD so sorry, but I think you've got a nice case of OCD lol. I don't have much advice for you I am sorry, because we can't really stop our OCD (unless maybe if you took medication for it, but I won't) so it might just be something you have to live with. I've learned though, don't fight it. Just let it be, because when you fight it that's when it gets worse and sometimes I don't even notice it if I don't fight it and don't worry about it.

By the way, it can also be caused with concentrating problems. I don't have ADD or ADHD that I know of, but sometimes I find it hard to concentrate which is why I have to read lines in a book several times over and over.