I can’t get over him

I got broken up with four days ago from my love of almost three years. I actually don’t know how to function without him here and I’m not sure what I’m even doing with myself. I just want to see a text from him and be able to not text back right away and act like this isn’t hurting me as much as it is. He’s blocked me, he’s gone. I just want my sweet boy back and I have no clue how to get over him. From everyone I’ve told they’ve told me to go get a different guy to hold me, hug me, and kiss me but I don’t want that from another person. I’m 17 and this man got everything from me, he was my first everything. I don’t think I’ll ever be able to do anything sexual or romantic with anyone ever again. I’m also in band and he’s in football which means I will have to go to all of his games to play pep band. I can’t stop crying and all I need is some advice from someone who was this attached to their partner. Please help.