I had that problem at first....try practising with a scrap film, both in and out the changing bag, until you overcome the fear of messing up the film.
Originally Posted by snaggs
Or see if you can thoroughly black out a room, maybe more comfortable than a changing bag. Keep a light-tight box available, to hold the film and reel, in case you get stuck or need a break.
Reels and tanks do take a bit of patience at first, but are much more convenient for smallscale use, and less likely to damage the film than the options (IMHO).