> I know she feels abandoned just as I feel
> I decided to break up with him, promising we would still be friends
> I started another relationship ... I couldn't stand his jealousy and bitterness.

Seems like you're not the one who was abandoned. The "let's just be friends" thing is a dagger in the heart of any man, more so to a still maturing teenager. I don't think he would be able to stand your obsessive clinging.

> love him more than anything in the world ... the truest thing I've ever felt

You may just ignore this, but there is no "true love" (or "soul mate"). There is lust, infatuation and family bond. Eventually the infatuation always wears off after one/two/three years, and if there isn't a strong bond beyond that, it's over.

> all the drawings and stuff I made for him over the years

Now that's creepy. I'd recommend dismantling the homemade shrine.

> I was pretty young
> He's 18 and I'm 17.

You're still very, young. There's more people out there, just don't blow it next time.

> Should I try to contact him again?
> And how would I explain I got his e-mail?

No, but if your insist on pouring salt on an open wound, go ahead.
Just drop him a line, tell him you searched for his name in Google. Be upfront about your intentions, and if he doesn't want to reciprocate, move on. There's probably someone at your high school who was a crush on you, but you don't realize it because your off daydreaming.