Why?

I went for the blood test yesterday. It was disasterous. I started screaming at the nurse. There was no real reason for this. She was slightly annoying. I've encountered her before and she is a bit of a bitch. But she really didn't give me any cause to scream a lot - which is what I did. I just sat there shouting 'Fuck, fuck, fuck .....' After she got me out of the room, I shouted it some more in the corridor. She shut the door on me at that point as I suppose she thought that it was all rather embarrassing for the other patients. After that I went into the loo and screamed more and kicked the wall until my foot hurt. I then wanted to go straight home, but it was throwing it down with rain, and it's a long walk to the bus stop, so I sat in the deserted foyer of the hospital for a while (it was 7 pm by then). I called my Mum and my sister and wailed at both of them down the phone. I usually try not to call them as I think they've both got enough problems of their own. My sister was great. She said, 'I think that was a fantastic thing to do. I think you should do that more often.' It was good of her to say that but actually the way I behaved was terrible. I don't know what has happened to me. Until two years ago I was always, always very polite and reasonable. Perhaps that's part of the problem. Perhaps I've been storing it all up for the last thirty eight years and the damn has finally burst. But I find it hard to accept this new version of myself. I remember all the stories that I've heard over the years of those people who've got cancer for the third time and they're still smiling at the hospital staff and being tremendously courageous and pleasant. It turns out that I am not like those people. I am not courageous or selfless or long suffering. Instead I'm on the edge, right on the edge. What do I do in this situation. What do you do if you know that you're losing your mind? I've got no idea.