
It sounds to me like its a symptom of your life being very overwhelming for you...at the moment.
I think your DH is a bit of a worry, the fact that hes not worried or adapting his plans in order to support his family properly.
I think you could do with going out to his gym the moment he returns, whilst he does the dinner, then he can go out for run or something after you get back and dinners eaten.
See if this, do e for a few weeks, makes any difference to how your life feels balanced?
I don't see a class issue, but interesting that you see it as one.
There are many very obese people.
Those that eat poor diets will suffer the worst of course and not just obesity,but all its inherent health risks.
Do you take DC swimming? It's a lot of exercise doing any movement in water so burns up calories.
I'd you don't have pennies for that, I'm sure she would love to be pushed whilst you run.
Or you can exercise at home also (skipping is a very intense exercise).
At her age you can also put her on in a safety carrier on a bike and head out on sunny days across country.
This will also help with the sleeping for her,with all the fresh air.
Exercise is free,there's no way you have to pay for a trainer or any other activities.
Also it will help with your own good feelings. If you run get the the couch to 5k app.
I do hope things improve for you, but you are a family so your DH should be responding as if hes part of a family too 