Omg.. I am so sorry to read about your Husband. Bless you both.
Now, 'bout your knee(s)? The first think I can recommend(speaking from experience)is try to loose the weight. I feel a lot better 10 lbs lighter. It's been a uphill battle. Fighting the 'impulsive eating'...seeking the comfort food. It is a common thing to do when stressed.
Get an RX for some PT. Make the time to take care of yourself. It is important.
Know when to stop. If your pain increases, stop what ever it is your doing. ie-- lets say that I'm cruising the mall. Your knee starts to hurt...really bad. You stop what your doing and sit. You don't wait to stop...you stop when it hurts. Give it 10-15 minutes rest, then move. If the pain continues..make an appt. with your Ortho.
I do wish the best for you and all the strength and power that you can muster up. It is so not easy at ALL to be in your shoes right now. Find a nice warm place, and get comfy...when you can.