Yes, I have a fear of fainting as well. I used to faint once every few years or so (it actually runs on my mom's side of the family for some reason!). I have done it in public as well. What is frustrating is that I tend to faint due to either a pain response, or because something greatly disturbs me, which I guess means the fainting is more psychological than physiological, which added to my anxiety. I haven't fainted since 2008 I think, so in a way I feel like I am due for it! It used to cause me a lot of anxiety when in public or when driving a car because I really could not control it and it would happen suddenly. For some reason though (and I honestly don't know why) my fear of fainting has decreased substantially over the last few years. Maybe because it hasn't happened for a long time. It does cross my mind occasionally (now typically just when I am driving, where I used to get panicky when in any public place, like a grocery store or even walking down the street), but it does not cause the same intense fear feelings that it used to. Again, I have no idea why. I can say that I have been on anxiety medication in the past (which helped me enormously) and I have been in counseling.
I wish I could give you better advice, but I thought I could at least let you know you are not alone!