ok the single meal a day thing is very bad, as you said it lowered your metabolism. so, go the other route, have about 6 meals a day. small meals. this will speed up your metabolism nicely.

in terms of what to eat - youve probably heard this already but: cut out junk foods, stuff thats high in fat, stuff with sugar in, chocolate etc. you can eat carbs, but try to cut out refined carbs like white bread and pasta. try whole varieties. try to get a good amount of protein in your diet (stuff like skinless grilled chicken, tuna, other fish, etc - if you go for red meat make it a very lean cut and only really as a treat). Eat your fruit and vegetables!! Seriously, buy loads of fruit that you dont mind eating (i love bananas... paging dr freud) and have them around wherever you spend most of your time (probably on the desk by your computer, or on a coffee table in front of the TV). If you can hungry and want something to snack on, hey you dont have to get up and go to the kitchen cus you have something right next to you. and its really good healthy food! so yeah have a piece of fruit, plenty of vitamins and minerals in there. Another major thing to do is cut out any soda. that doesnt mean only get diet soda, kick it completely. try drinking water instead. its gonna be weird at first but after a few days you should be ok. you should drink quite a lot of water, as this is great for your body, speeds up your metabolism, is used in building cells etc etc loads of useful stuff

now, the main thing to losing weight is to use up more calories than you take in. google around and try to find out a book or an online thing that can calculate how many calories you personally burn in a day. then, watch what you eat and count the calories and make sure you eat less than you need to sustain the same weight. you dont want to try to lose too much weight in a quick time period, as it can cause further health problems as well as aestetic problems (lots of flabby extra skin that may require surgery). 1 pound a week is not being over-optimistic. you may be suprised at how easily weight can drop if you are careful about your calories. but dont lose more than 2 pounds per week! this is the generally accepted "safe weightloss" max.

i would focus on losing weight via this kind of dieting first, and think about taking up exercise later on when youve lost some initial weight, so that you dont overstress your ankle and back (as well as any cardio problems).

right just need some kinda disclaimer: go see a doctor. srsly. go to your gp and say that youre trying to lose weight with this kind of diet ive outlined. it can be dangerous to suddenly change eating habits so drastically, so get their advice on the matter. it may be that you need to cut down on bad stuff slowly, rather than going cold turkey. your doctor will know best about what method to use to cause the least strain on your body. also, keep checking up at the dr as you lose the weight, so s/he can check on the condition of your back and ankle and decide when you can take up light exercise such as walking.

good luck, you can do it and there are people out there to help you as long as you give it your best shot.