
Trekfan,
I've totally been there with the recurring nightmares. What you're going through sounds like Post Traumatic Stress Disorder - I'm guessing that your period of being overweight was pretty traumatic? Beyond looking and feeling better now, I'm imaging that there's bigger reasons you don't want to go back there.
What you're trying to do in response to the dreams - rationalise the fear, or escape from the fear, you've got to face the fear. I read a story once about a woman who had been raped, and kept having a recurring nightmare where a faceless man was chasing her. After months and months of this dream, eventually she one night she had a lucid moment in the dream, and she faced the man and asked him what he wanted. He came up to her and said "I have something that you dropped. It's your self respect." She didnt have the dream again.
You might want to look into some techniques for lucid dreaming if you want to try something similar but - you don't need to be asleep to confront your subconscious fears. Just sit with yourself for a while (mediate) and just listen to what your mind has to say. Don't rationalise anything. Just listen and understand.
You'll be fine 

Originally Posted by
Knifegill
I guess I should elaborate on laughing at scary dreams. It helps to do some meditation and lucid dreaming, along with assessing your life in its entirety and throwing away all your fears. Once you're okay with dying and realize how insignificant you are in the universe, the thought of being concerned about the possibility things hurting you becomes laughable. There is no fear (deep in the mind, it is gone!) once you've embraced death, pain and mortality in entirety. Most fears will vanish entirely, and the rest will shrink. Spiders still make me think, yes, but it's more a duty to react rather than the hot, panicked flashes of terror I used to get. And after lucid dreaming, I've died in dreams a lot and not given a darn. Marilyn Manson shot me in the face, I've been stabbed, crushed by things, chased by monsters and I laugh, and just keep dreaming. I think, for vivid dreamers, mastery should be taught to the young.
Knifegill, I'm imagining that most people won't know what the hell you're talking about here. I do
“I'm glad mushrooms are against the law, because I took them one time, and you know what happened to me? I laid in a field of green grass for four hours going, "My God! I love everything." Yeah, now if that isn't a hazard to our country..."
― Bill Hicks
"Sometimes eating the wrong food with the right attitude is a better choice than eating the right food with the wrong attitude... That’s how powerful the mind and the heart can be in the healing process."
- Chris Kresser