You will one way or another face loss in your life. You cannot avoid it, and you cannot fight it. Trying to will only serve to extend the pain of it.
My best advice is to let yourself mourn, get angry, sad, do what you need to do to get through it. That gut wrenching feeling of aloneness is painful, but remember that it's okay to feel like that. Reach out to anyone, whether it's online on a roleplay forum, or outside.
Loss comes in many forms; relationship, death, health, many things. None of these are easy, and don't let people tell you when to move on.
Only you can do that.