Let me say first that I am sorry that you are going through this. I know what its like to lose friends/relationships due to the actions caused by our various disorders. But truth be told, I firmly believe that if she was able to write you off this fast, she wasnt as invested in the friendship as you were and this may be for the better. I cannot tell you how to get over it, though, as that is something that takes time. And while it hurts like hell right now, as time goes on it will get easier. You learn new ways to keep yourself busy, you meet new people and you move on. It also could be that your ex friend doesnt know how to cope with someone going through what you go through and it was too much to handle. Maybe in the future you two will reunite and this will be water under the bridge. You never know what may happen in the future but do not let this break you. You are stronger than that, I know it. Best of luck to you.