I replied to your other comment without being sure whether the "nothing works" part was about weight loss or the ability to gain strength and conditioning from exercise.

There is a current idea that exercise is beneficial no matter what you weigh. See for example http://haescommunity.org/ and this new article on exercise and depression: http://www.huffingtonpost.com/lloyd-i-sederer-md/depression-treatment-_b_819798.html?ir=Living

I have a hard time not following the herd mentality and trying to measure my success with exercise by my size and shape. I can and generally do use another measure of success for exercise than what I weigh. You can measure increased strength either by seeing how much weight you can lift or how many push-ups or pull-ups you can do, or you can measure your increased cardiovascular fitness with your standing pulse rate, or how long you can walk or run without becoming exhausted. (I'm shooting for 45 push-ups in a row by age 45.)

Then it doesn't actually matter whether you're metabolically privileged. Or privileged with relation to losing weight anyway, some people would say your metabolism--and mine!--make total sense in a starvation environment. The problem getting the endorphins to let down is a big disadvantage, but you may be able to figure out a duration and intensity of exercise that will release endorphins. (And that would be a good goal to replace weight loss, too.)

I think the main thing is to stop walking over broken glass to get thinner. Where's the utility in that? Exercise is still going to benefit you, even if you stay at your current weight and grumpy every minute of your walk.

I don't think it's easy to give universally-applicable exercise advice. If it were, there wouldn't be such a huge market for exercise advice! There seem to be changes in how exercise physiologists think about certain exercises every few years. Separate abdominal strengthening exercises, for example, seem to be out of vogue with some trainers. So one piece of procedural knowledge is, you have to read about exercise, it's not trivially obvious how to do it.

If I were going to try to give someone a universal piece of advice about how to get started, I wouldn't say, "don't bother with other things, try pull-ups and tricep dips," because only a small percentage of new exercisers can even do those exercises. I'd probably say, "try taking a walk." (But even that isn't universally helpful, since lots of people have problems with their knees and ankles or hips or back and may need to start with something even lower impact, like swimming or yoga.) So a second piece of procedural knowledge is, everyone's body is different, so the exercise you pick should reflect what you like and need.

Addressing the problem you pose here: Since walking is a low-impact cardiovascular exercise, why not try it for an hour every day instead of two hours every other day? That will help build endurance and make it less taxing. Or you could start with less and increase a little every day. There's a third piece of procedural knowledge about exercise: you can increase your capacity if you add on slowly and sneak up on your body, even if your body is being recalcitrant.

I'm not sure what you mean by "immune to exercise." Are you not experiencing endorphins from your walk? Is your heart rate staying below the target rate? Some good procedures are to walk with a friend and make sure you aren't going too slow or too fast or bring music if you're going to walk on a treadmill by yourself.

And if you think you'd enjoy Dance Dance Revolution, I'd say do it in your glasses--you can always wipe your face with a towel when you get sweaty. That's what I do in the gym. I recognize that no one REALLY needs equipment to be fit, but--if you want to do that, why not? Isn't fun one of the goals of exercise?

I don't see a widely informed consensus about how to exercise and I don't think it's in the same category as some of the other questions on this thread. It's not an ordinary skill--there's a lot of mystique around it.