We have a woman in spinning class who tilts her saddle WAY up - I can't see how she can stand it. Perfectly level doesn't work for me, I always feel like I am sliding off the saddle though it looks perfectly flat. Just the slightest tilt up works for me.

Settings certainly make a difference, for sure. Can you work with your instructor again to determine the correct settings for your bike? If your seat post is too high, that will cause comfort problems for your girly bits, and sometimes it can be difficult to tell just what is causing the problem. Of course, this assumes the instructor understands fit, and if he isn't a cyclist he may not really understand it.

Personally I have found bike shorts to be far more comfy on a spinning bike than the padded seat covers, but that is me.