Hey,
Although Im not yet an instructor, I find spins extremely unpleasent. I always had a great fear of spinning when practicing stalls, so anything to do with slow flight and the like was dreaded.
My instructor new fine well that I hated it so he broke me in gently. Doing an incipient spin, which he gradually built up. We never did a full spin, until my PPL checkride, where, as usual, I tried to recover from a stall too early, but the left wing dropped, so I began spin recovery.
My examiner asked me why I was doing that, and I told him I thought we were starting a spin. He said 'no lad, thats not a spin, this is ..................'. Needless to say, it wasn't as bad as a thought it was, in fact I was giggling, kinda like what you do on a rollercoaster :-) But I think this is because I was built up to it, and not thrown in.
Saying as I hope to instruct in the near future, I also worry about spinning, and any other 'weired' stuff, and I always think I will struggle at this aspect of training. In my defence though; the plane was 30 years old, perhaps spinning something newer would calm my nerves a bit.
I think its quite a common thing to cause anxiety; it feels awful, and I agree with an earlier post, as my fear is also not being able to recover.