Keld's interpretation may be correct, and if so that is pretty creepy.
What I thought, and that, Gem, I don't think you need to worry about, is simply that he liked you. When you like someone, you want to hang out with them all the time. That, in itself, isn't a problem. Especially as you said you two were "nigh inseperable" - perhaps that changed for you, but not for him? That is, he was doing the same things as before his confession, but for you the situation had changed and "nigh inseperable" had become "he won't leave me alone"? In any case, it wouldn't have been unreasonable to request that, say, he hang out with some of his other friends for a while.