WHY CAN'T I GET OVER HIM!?!? THESE FEELINGS WILL NEVER GO AWAY?

They will, I felt that way once but I got over it in time, just cut off all connections with him and look at him not for the good things but for the things he did wrong. Then when you are over him reflect on what was good

You don't think you are the only person, surely? Virtually every adult in the world, I suspect, has been through similar experiences.

People fall madly in love, but the ecstasy, excitement, strong passions and desires, and high emotion are very hard to keep up, so eventually we start to come down, typically after around 18 months to three years. If people are friends, discuss their mutual values, shared ambitions, interests, etc., in some depth (obviously there will be some differences, which help make relationships interesting), and make plans, work on their personal development, etc., this can develop into a long and wonderful relationship. If one party feels insecure or low in self respect, it can make for a difficult partnership. It's easy to behave at our best when in love, but marriage involves a lot of self discipline, sacrifice, compromise and flexibility.

Teenage & 20s marriages are so very often disastrous in the longer term: it's very hard to get to know and understand others until we get to know ourselves, our own needs, etc. which are still fluctuating a bit until we are "mature" (often, but not always, of course, women in later 20s, men mid 30s). Hence, adolescents' feelings often fluctuate somewhat. This is a very good reason for avoiding the emotionally bonding sexual intercourse, as it can so often lead to serious mental and emotional confusion unless in a of a deeply loving, mature and well established relationship.

Time heals emotional wounds just as it does physical ones. If you keep picking at a scar, it takes much longer to heal.

Try to develop more emotional self sufficiency and self respect. You can't "not think" about him and you relationship but you CAN replace the thought with other ones; your friends and family, sports, work/studies, etc., etc. It takes self discipline, and it's a part of growing up.