Ok. First things first. You are going to have to make a spreadsheet and keep track of your caloric intake, protein, fat, and carbohydrates, along with weight and maybe even body fat %. That way you can track your progress very carefully and make changes. Also, try to keep track of your excersise and lifting progress.
Your goal is to try to maintain body composition while slowly losing fat to reduce loose skin and stretchmarks. Which is going to require not losing any lean body mass and building muscle at the same time while decreasing your body fat %. This is going to be a slow process to lose 80-90 lbs, but its achievable.
I think there have been threads before on loose skin and stretchmarks, I think people have recommended aloe vera, cocoa butter, and Vitamin E, and there are also specific products made to reduce these, but you can search for those or ask in another thread for people with personal experiences.
Also, foor healthy skin its important to drink alot of water and always stay fully hydrated, and I would recommend an EFA supplement also. I think it has been stated that soy protein is good for the skin too, so you might want to look into that also.
Remember eating right should be a lifestyle not a temporary fad, like most diets are.
Like I said earlier, try to get a diet together and put it into a spreadsheet so you can see your total intake and then start to make some adjustments.