If you met this person online, why don't you take a break for a day or two and get your thoughts straight? There is no need to rush headlong into things. Tell them that you're concerned this is moving too fast and you want a little time to think. If he is that close to you he should respect that. Just give yourself a day, just one day. Take a deep breath, do something nice for yourself and think about what you want out of this relationship and how you want that to happen and develop. I'll be thinking of you.