I just graduated from high school and i feel bad. why?

Its not only the fact that I won't see my classmates or teachers because i never really made a lot of friends, i was on the weird, artistic and individual-like side of high school, i wasn't a nerd or anything but i was always different than the others or so they say. So yea its not like i'm going to miss them but like i feel this weird empty feeling inside, its like i don't really know how my life would be like without all of those assholes. And i wasn't a good student i'd rather read a book or draw during class than do my classwork and now i feel like i should've shown more discipline and effort. idk. Is life actually getting better after high school? Is it actually good to be weird and different as an adult or will i always have to suffer from the regret of society? its not like im physically disabled lol or like im ugly its just my personality and my artistic style i guess.