Hathop

I am in this choir, it's an amazing choir, and I love being in it, but every time we go to perform, I get really overly nervous about fainting, and if it is a really big competition I often get nervous ages beforehand and it affects my trip. We are about to go and compete in the national finals, and that is what's happening again. I know my fear is completely irrational, because I have never actually fainted on stage before, although I have felt really dizzy and as if I'm going to drop. The biggest problem for me is the mental side of things. Sometimes I get myself so worked up about it and then start panicking on stage, which I'm afraid will make me feel faint even though there is no reason to be.
My worry is quite strange because, being a singer, I do lots of solo performances, but in those I never have the same fear. I think I am just really nervous of letting the choir down (although people say that if I do faint, it won't affect the marks) and making a fool of my self in front of a big audience.
I have spoken to teachers about it, and I am going to talk to the conductor, and they have given me good advice about many technical things, like how to stand, have lots of sugar and stuff , make sure you keep breathing etc, but they haven't really addressed the mental side the problem, which I think is more the issue. The teachers have also said that if you feel faint or something, run off stage or sit down, but I think I would rather faint than do those things, so it doesn't really console me much! I am not afraid of hurting myself or anything, it's more what everyone else will think.
I know that the best thing to do is face your fears, or so people say, but the trouble is there are no real opportunities to face them before the competition, and performances are so wide spread that I can't just do it over and over again until I feel comfortable. I also really don't want this silly fear to ruin my trip, because I love singing and it will be so fun, apart from that!
Please give me some advice!!
Hathop=)