Starting over again

Howdy, I live in Mocksville, NC ranked the number one redneck place in North Carolina. LOL I am 52 years old, married, mother of 26yr old daughter, wife to disabled husband, disabled couch potato. I need to loose over a 100lbs. I started out losing weight 7 years ago right before I became disabled. I was diagnosed with blood clots filling both lungs August of 2012. I had lost from 420 lbs to 312 lbs and was working out for an hour 5 days a week. M W F was cardio and T Th was strength training. I never thought I would enjoy going to the gym, but I did until that horrific day that put me in the hospital for a week and now restricts my activity due to shortness of breath. I also have severe osteoarthritis in all my joints, especially the knees and back. I need knee replacements but I have to get my weight down to 40 BMI and I am at 52 BMI. I have type 2 diabetes and taking metformin to help with that. I know the exercise will help with that problem. All the encouragement is welcomed. Please. I know I can do it. But the couch potato, self pity party gets me thinking differently. Hope to here from others. Good Luck to you.