Confusing is putting it mildly

I really like this guy and he says he loves me and I have said it back... I think that I meant it. But I have so many thoughts and fears...
I haven't met him officially.
It's the whole online thing but a bit different too. He is my best friend's brother's friend. I have web cam'd with him a lot of times and talked on the phone and texted like every possible second for 4 months.
I love him, I know I do... I am pretty sure I am kind of in love with him, but I can't be 100% sure until I meet him in person.

I know it's frowned upon to have online stuff but it's not like I have no connection with him at all.