Wow! It seems everyone has their two cents to add... If only we ALL were in a position to give advice!
Loz, I'm not sure why you feel you can't exercise, but... You have to. Besides, there's no better feeling than being in shape! Regardless of age. Don't listen to those who say to cut carbs... You need carbs! Just go easy on the simple carbs, stay the HELL away from: table sugar and high fructose corn syrup. Go easy on the potatoes and bread. This is by no means cutting out carbs! Just go for the complex carbs. Learn to LOVE veggies. Oats are the best way to get your carbs in IMO, or Ezekiel bread is good too. For protein eat lots of fish, chicken breasts and egg whites, and also the occasional LEAN steak or roast. Tenderloin or filet are good.
Eat regularly, eat often. Don't starve! Don't go for the Atkins and for the love of Thor don't go vegan! Animals were meant to be eaten! Otherwise they wouldn't taste so good.
Dont go on a diet, or the results will almost definitely be temporary! You're going on a lifestyle change, not a diet. Don't do cheat days, but have the occasional cheat meal. After a while, you won't crave carbs, sugars, etc.
Best of luck on your transformation! Be sure to keep us updated.