Great post GAF, I'm at the same stage as you,I think,and like you I have developed this uneasy feeling.
I don't know why and I can't explain it but it's comforting to know that I'm not alone.
Perhaps I need to talk to someone other than my instructer (I wouldn't feel comfortable telling him in case he thinks I'm a wimp!)
Anyway your post has definately made me feel better, so like you I'm going to soldier on.
The funny thing is when I actually get airborne I do enjoy it..... so onwards and upwards.
Regards
Cloudwatcher