the worst breakup.. please help me

my boyfriend and i broke up on Monday. two days ago. we had been dating for 10 months and talking for about 3. We’ve been through so much. He’s always had depression and then once we started dating, worrying and overthinking got worse. i told his mom about everything and she finally got him an appointment. he got on antidepressants but then they ended up changing him. he showed me less affection, didn’t care to see me as much, stuff like that. when before the meds, he was the most perfect dream boyfriend, i swear. the only downfall was that he got so sad so easily. we broke up because he feels that we would be happier without each other. him not being able to love me the way he used to hurt me so much. and that hurt him. he really believes thats the best idea. he says he can’t change himself or the way he is. he’s the love of my life. i can’t let him go like that. we were supposed to be forever. we always talked about our future. i want to fight, i want us to fight for each other. he has given up all hope. he doesnt think there’s anything we could do. i tried talking to him about therapy too and different medicine. he wasn’t having it. i feel so empty now. so broken. i have no purpose. he was my love, my everything, my life, and my world. i’m having bad thoughts. i can’t live without him. somebody please help me..