need advice asap

This boy and i have been friends for 3 years, he’s the only person that has stuck with me and i considered him my best friend. we liked eachother on and off for a while but nothing ever happened. he started dating this other girl and it really hurt me hearing him talk about it. i tried to be happy for him and i really want to but i can’t because i’m so upset over it. i decided it would be best to take a break from him and move on but it only made things worse. it’s been three weeks of not talking to him and every day i think about him so much. he probably thinks i stopped caring but i just was trying to do what was best for me and i don’t think it was. i don’t know what to do.