Being thin is scary for me too. But I'm losing it so slowly that I think I'll have time to ease my way into a small body. And if I hate certain kinds of attention (which I do), I don't have to go around dressing like a hoochie! Its one of my personal myths that being thin means I have to dress like a hottie everyday. Really, thin women can hide in baggy clothes just as easily as I hide under fat layers. And I'd much rather do the former than the latter. It also doesn't mean I'll be bombarded with attention. I do get attention when I'm thinner, but its not like I'm being chased by the paparazzi or something! But these are bad things I envision when I think of how life will be when I'm thin. I also get afraid that I'll have to obsess even more about food to maintain the weight and I worry that if I gain any back, people are going to either be disappointed or say, "See. Once a fatty always a fatty. She couldn't stay thin to save her life." And they'll all laugh at me, like everyone has always done.
Part of why I remain overweight is because it gives me excuses and lets me hide and when I'm thin, I feel like I'll remove all those reasons and a part of me needs them. But plenty of people I know who're thin still hide. But to me, fat=safe. Thin=exposed for all the world to see.

And for someone like me, that is a freakin scary notion.
In closing, I'm filled with all sorts of myths and irrational conclusions about how much pressure its going to be on me to be thin and stay thin. Those thoughts keep me here at this unhealthy weight that interferes with basic functioning in my life. Learning how to let go of those fears and myths is part of the process for most of us, in my opinion. Especially those of us who have never truly been thin and don't know what the **** to expect.
You can see by all these posts you aren't alone. And hopefully what I've shared about my myths and fears make sense to you.