I'm cursed with nostalgia

It seems ridiculous, but it really wears me out. I graduated from my high school last year. And today I went to the school to receive a certificate of internship! But I didn't really like the school not the teachers and the staff, it was my colleagues and the teachers didn't like them, because they're egotistica and arrogant! I don't like them for this reason. And I went to another uni, not the one that the majority of them went to! All my teachers All the teachers welcomed me lovely, I missed them too so much, I talked with them and talked with younger year! I missed the school and my teachers so much I wish if I had had in the school and I had never graduated! Funny isn't, how much I hated the school and wished to graduate badly! But now I wanna get back to these days, I missed it so much! And now I'm at home with a bad mood, and I wanted to stay all the day in the school, but I didn't sleep last night, and I mustn't have stayed. And now I'm staying at home listening to musics that I used to listen to it when I was in the school to bring the feelings! Nostalgia prevents us from growing, but I wanna overcome it, and I don't what to do!