How to get over someone

So I’ve loved this guy for 4 years now we talked on and off close to dating a few times met eachothers parents, I fell in love with him he has hurt and used me but I can’t move on there is something about the way he looks at me I can’t get over, I hope to marry him one day but for now how can I move on from someone that’s been a huge part of me and who I am and my life it’s just so hard to let him go ?! This may sounds ridiculous but I’d rather not put the whole years up here so how can I try move on ?