How do you lose weight with a terrible metabolism?

I have got to have the world’s worst metabolism. I used to weight 340lbs, but over the course of two years, lost 110lbs. Unfortunatly, I gained back 40, but am still significantly smaller than I used to be, so I’m happy about that.

The problem is, my body reacts extraordinarily poorly to eating and exercise. The only way I was able to lose the 110lbs was to spend hours upon hours each day working out (long 2-3 hour walks daily, and 1-2 hours in the gym 3-5 times a week) which I just don’t have time for (nor do I have transportation to the gym anymore, which is a distance away, as I cannot afford a car and have to take the bus everywhere). In fact, coupled with my recent breathing problems, I can barely work out at all without becoming light-headed and ill. And eating is insane for me. A single, small, healthy snack- even an apple, will cause my body (particularly my belly) to bloat up to nearly twice its usual size for up to 12 hours (once or twice, even a full day), and if I eat more than one meal a day, my weight will dramatically shoot up, as though my body is immediatly converting everything to fat. I’ve gained 10+lbs in less than a week and then had to spend a month losing it because I ate regular, healthy meals 3x a day and wasn’t able to work out constantly.

It’s really becoming completely insane. I feel uncomfortable eating, and try to only eat one extremely little, because I’m afraid of how badly I bloat and the damage putting on more weight will do to me, even though I know not eating will do even more harm.

Anyone else have this problem or any suggestions?