I really miss my ex

Okay, I'll start this off by saying that I am mentally ill. I was really dependent on my ex and they were to me as well. We broke up because i had a really bad depressive episode and basically ghosted them. I apologised but they have no interest in rekindling our relationship even after us being bestfriends for years. They have new friends that have hated me since i met them also. Since our falling out they have been avoiding me in school and making bad decisions. It feels like they hate me but a mutual friend of ours is very adamant about them not hating me. Either way, I really miss them and want to be friends with them so bad but I really can't just wanted to get that out I guess.