I went clipless last year and LOVE it. But I can relate. When I took my bike in to have them put on I was terrified and had nightmares that I would hate riding and not go anymore (didn't occur to me I could just put my old pedals back on)
I went on my trainer to practice then I hauled my bike to the park and as they said just went round and round and round clipping in and clipping out.
The next day I did a 48 mile ride :P
One thing that helped me; was on my long "real" ride the guys I was riding w/ would remind me to clip out as we approached different things.
A riding partner just went clipless and I do this w/ her too now (ex we were riding across a narrower bridge in the park and some little kids were coming towards us. I reminded her to clip one foot out and pedal w/ the other in case the kids did something unexpected and we had to stop quickly.)
EVERYONE I have seen fall has done so at 1mph or less. It is more of a "tommy tip over" than any semblance of a crash. Now I figure, if I am going to crash big time, it would happen whether I am clipped in or not. In fact I had more falls BEFORE I was clipped in then I have had since being clipped in. Go figure
Good luck and go for it - you will love them
It's about the journey and being in the moment, not about the destination