Do you only regret it because of the reply you received from him? I think what you have put here is really touching and nothing to be ashamed of. If he told you the same, then I'm sure you wouldn't have regretted sending this.
Feeling it wasn't as bad as saying it. By doing so you've become vulnerable.
It sounds very heartfelt and loving, what you wrote; it displays your vulnerability at loving that other person, and it's both touching and beautiful to read at the same time. You put your feelings right out there on the line so that person can realize how much he means to you.
You're infatuated with someone - perhaps it's even love. But you're worried it might not be reciprocal. You're both pretty young, so it could be a little early for total commitment. You'll be OK irregardless of how things work out - you're smart, sweet, and stronger than you realize.
It's sounds like obsession or serious infatuation. <br />
Depending on the person you sent it to (personality wise) it could either turn out to be great, good, or bad.
If you have lived with that person for 5 years or more then you sound blessed.
It sounds like you're going down a dark path of obsession.
I'm not sure.