How does it feel to be hypnotised? from Ophelia's blog
Here's a thread I found over on reddit, that asks:
it contains literally hundreds of accounts.
I was lucky to have my first first hypnosis experience with a very good hypnotherapist who did an excellent pretalk, followed by the Chevreul's pendulum suggestibility test, which acted as a complete convincer for me when it worked brilliantly. During the induction, when I couldn't open my eyes after he suggested I try, I simply knew that even though I was quite aware and didn't feel anything but nice and relaxed, I was in fact in trance.
The thread also contain many accounts of how people felt when they carried out suggestions, many of which mesh with mine.
If you'd like to add your account of how it feels for you to be hypnotised here, feel free 
The Wall