I think I might have been having too much some days. I've pretty much gone off coffee but I love Earl Grey and although I do have decaf occasionally, I don't like it as much. I sometimes have 4 or 5 big cups a day, and I just read that you should only have 2 mugs or 4 cups. However I also read if you only steep the teabag for a minute, the caffeine will be a lot less than if you do it for 5, and I only do it for about a minute anyway.
I guess I just need to watch my intake, and have decaf more often. x