My Own Obsessive Fanboy?

For the past few months, a fifteen-year-old boy has been following me around the internet like a child. I'm a nineteen-year-old Jill. I've never met him in real life. I met him through a site I post my art on, but ever since I've been practically guilted into giving him screen names for almost every instant messaging account I own. I even gave the kid my phone number and now he texts me like crazy. Big mistake on my part. But what really kills me is the fact that he looks up to me like I'm some sort of super hero. My art, my writing, just my thoughts in general. He replicates my style (which is a bit irritating), started a story with my character, and has to get my opinion and guidance all the time. He's a nice guy. Really sweet and genuine. He believes that internet friends shouldn't be cast off as dispensable since they have no relation to you in real life. He's loyal to the core, perhaps the most loyal person I know, but he's also really obsessive. He is rather clingy and kind of gets on my nerves by acting like an attention-starved eight-year-old all the time. I've complained about him before to people who all said "Just ditch him" or "Tell him the truth", but there's a problem. He really looks forward to my time. He looks to me like a big sister. He also wants all the time he can get with me...I mean, ALL of it.

Today, after I came home in the evening, knowing he'd be home, and checked a site I log onto daily to see if I could spare some time to myself without actually logging in. He was offline. But, as soon as I log in, not thirty seconds later, he logs in as if he'd been waiting for me. It freaked me out a little, not to mention frustrated me a bit. But then he proceeded to tell me that someone else from the same site he trusted started to insult and harass him. This happens to him frequently, as made apparent form what I've seen in the past.

I just don't know how to tell this poor kid to let go of me with out hurting him.