Well, what I have to say to you is that things do get sour sometimes, in any kind of relationship. It simply happens, and when it does, it's more productive to first: think logically on what's caused this situation, and second: act accordingly. If you say that you have the blame, and I don't think you did because problems have causes not guilty ones, you should probably analyze what has happened and talk to that person. I know it's hard and I know these things hurt, because they can put you in heaven or hell, emotions that are connected to relationships and to other people, people we care, are very powerful emotions, and they can go up or down.
So my advice is: don't let yourself be demolished or disturbed by this thing. Let your emotions flow naturally, and when you feel you can go ahead, or when you feel you can try to repair what happened, then you go on and move... It's all up to you, you just have to keep your mind in order, and everything else will come up right...