I am going to be brutally honest with you here - you need a break.
You can't shoulder all of this on your own.
Losing weight and riding requires that YOU make YOU a priority, even to the point that some might see as selfish. I personally think that it ISN'T selfishness, but that we, as women, shoulder so much for everyone else because we have caring hearts and a desire to help. I think we are made that way. What I see as happening, though, is that resentment comes when we are overworked, overtired, over-ran, and lack time to do things that are for us. Only us.
I personally think that we do it to ourselves. We need to know that it is okay to ask for help, to delegate chores to others, to tell our wonderful husbands that we have too much on our plates and ask for their help, and to pay for help when we need to. I also think that sometimes we need to lower the bar on the standards we set for housecleaning. I don't know if that is an issue for you personally, but I have really learned that spotlessness isn't good for my sanity.
Here's what counselors say to do:
Write a list of all of your responsibilities. On the left hand column of a paper, write down all of the things that ONLY YOU can do. This includes time for exercise and making healthy meals. And sleeping!
On the right hand column put any other tasks. Cross out those that really aren't too crucial and see who can help with the rest. Include your son and husband.
I hope that you get some rest and find some time to have some joy and time for yourself. Please don't feel bad about sharing. So many of us have experiences that are so similar and I am sure you will get a treasure of advice.
HUGS!!