How long does it take to get over someone...?

you are in love with. I'm only fifteen, but I don't want to get into the messy details that surround love and being too young. He left me four months ago, without a reason. We dated for nine. He started dating her two weeks after we broke up. He was my first kiss, the first person who caught me because it seems like there's nothing imperfect about him. It was longdistance, and we have no mutual friends, so he had the ability to disappear forever which makes it seem like he was never real in the beginning. I still cry hard until i get sick. I feel so insane sometimes & I have no self worth anymore. I let someone use me because somewhere i sickly thought it would bring him back, make him want me. That caused me to lose my close circle of friends as well as my best friend. I miss him every second of every day. When will this end?