How do you get over a broken heart?

I dated this guy for about a week but we were very good friends before then. I fell for him so fast and he eventually did and asked me to be his girl friend. We started out very fast and we had sex very soon in the relationship. But everything was going good. He had taked my virginty so i felt very close to him. He had even told me he loved me. But about 5 days after we had sex he broke up with me for his ex girl friend over a text message. I cant sleep at nigth without cryin cuz he hurt me so bad. I gave him something that i kept for 17 years and now i dont no what to do. How do i get over this. I no he used me but i still miss him.