Breaking up with one of your best friends

Me and my ex met each other as friends, we slowly fell for each other and became the couple of the group. Now we broke up because of many fights we had, we still have a lot of feelings for each other. What’s bothering me is that since we all live in same dorm, we slept almost every day at each other’s place, basically 98% of our lives were together, now i cannot even sleep in my own room because of too many memories, I slept in his arms all the time do the loneliness is too much, also i have to see him almost every day because I don’t want to destroy our group. I miss him every day, it’s difficult to be in same room with him and not at least hold hands like before. I don’t know how to move on or what to do. I just feel like slowly I’m getting more and more depressed and weaker.