Speaking from experience, I had a lot of trouble losing weight, regardless of how much I exercised. In my case what I was putting in my mouth was far more important than what I was doing at the gym, when it came to weight loss.
I didn't start losing weight until I cut out all sugar, wheat, cornstarch, and starchy veggies. That means no rice (white, brown, wild, all out), no bread (white, wheat, pumpernickel, multigrain, all out), pasta (regular and whole wheat), cereal (again, whole grain, whole wheat, etc, all out), and no potatos (not even sweet potatos).
The irony is that I made these changes because I have heart disease at a very young age, and these food types are known to act like gasoline on a fire when it comes to heart disease. So I cut them out with zero thoughts about losing weight.
But, once I changed my diet, I started losing a pound a week, every week, for several months. And I was doing nothing else differently. It was pretty amazing. I finally "stabilized" around 160 lbs, which I don't think I've been at that weight since high school.
Not to be critical, but to put your own health in jeopardy for a dog doesn't seem like a fair trade. I love pets, but I would continue to work out and eat well. If you aren't working out. Are you at least eating right? Fruits, vegetables, cutting down or completely doing away with sugar. Also stay away from fastfood and processed foods. Do these things at least and you'll maintain until you get back on your exercise routine. Good luck!
There are other things you can do in your spare time like walking the dog, cooking home meals from scratch etc.
Ive found some excellent recipes on the internet that are healthy and come from ingredients that you and I probably have in our cupboard