Hi Kimmy,
Haven't read the whole thread but wanted to add my thoughts.
You can lose enough weight to feel confident for the wedding but don't obsess about the long term, focus on now and what you are doing and eating today.
I have clinical depression and I now take citalopram which is helping a lot. This is after years of both mild and severe depression and always being against drugs but it is making a massive difference. I am also loosing my depression weight on it. Perhaps you can adjust your medication if it is not working?
I have used diazepam but it is no real answer to the insomnia. It is addictive and you build up a tolerance, doesn't address the underlying problem either.
I have bought a bike and it makes me feel amazing whizzing around on it, about 7 years old again. It helps with depression and it is good exercise. If you have any nice cycle paths nearby you could try this or perhaps there is something else you would really enjoy - that is the key to exercise for me - enjoyment.
If you want to lose weight and like cooking and good food I cannot recommend this book enough. I don't follow diet plans as I find the food boring and this is not a diet plan, just some delicious recipes that happen to be good for losing weight. It is obviously a question of finding what works for you and you could use the book at home until you feel better enough to go out.
I agree with whoever said home-made soup and disagree with nuts, I put on most of my weight due to nuts - they are high in fat and that is why animals want them for the winter .
Hope that helps.