Im having a pity party and you are invited!

Lately I have been really sad, easily hurt and overall frustrated. I have the normal worries everyone else does, money and health etc. Not to get into anything super personal, I am being a total whiner, but like everyone else I am entitled. I cant always be peaches and cream, happy go lucky and all that crap, all the time. I have melt downs and bitch fits too.
I am often if not always there for my friends and family when they need to have melt downs. I do not know if its my personality or what but I tend to not share my stuff with others, when I melt down it is usually on my own. So this last week I am having one, they don't come often cause I like to live drama free and let things slide. But I feel so hurt and angry at one person in particular because of their reaction to my having a melt down and this has compounded my feelings. And I feel vulnerable right now and it sucks ass. Not only did I think of this person as my best friend, I thought of her as a sister, a family member. When someone comes up to me and is in near tears and says that they are losing their mind has a heavy heart, my reaction is to not say, well we all know that you lost your mind, or oh maybe you are going through the change, or even, maybe you are PMSing. My reaction as a friend is to say, whats going on? Do you want to talk about it? Is there anything I can do to help? Not from this girl it is bullshit like the aforementioned. It could be that I am being over sensitive or just angry. But dude that was the wrong thing to say. I have done nothing but be there for her, when she had breakups, when her kids were assholes. When she just needed an ear, I was there. There were no rude comments, no hurtful words. Just listening and giving kind words when I felt they were needed. In reflecting on this relationship she has been an overall good friend, I think about it and think, shoot maybe she is going through something and needs some one to listen to. I feel bad because I wont be that person anymore, I cant. It is a heavy heart that I carry right now. I wont blame her for anything cause she isn't the reason behind my original feelings. Breaking up with a friend is a hard thing to do. I hope that none of you should have to do this.