What do I do in a situation like this? advice?

last week on wednesday i told my crush of 1 year that i liked him and he told me that he's done with relationships because of his ex gf she messed him up. he told me not to change because i'm still his best friend. I constantly have to see him and it really hurts and every time i start to think of getting over him or i'm halfway there he starts a chat with me or he likes a photo of me. Like on saturday i had to see him in the morning because we had a soccer match and we're on the same team it was awkward when we said hi but after that it was alright though we didnt have the chance to talk much. Later that day i was just starting to let him go and for the first time ever he starts the chat and acts all cute.

All my friends tell me you're going to be fine nd yeah i will be with time but he's my best friend so seeing him kills me...

All i'm really asking is any advice?