I am sorry to hear about your loss and I know what that feels like. You've been through alot as well with your health. By any chance are you on antidepressants? I took Celexa during my husband's illness and death and I gained tons of weight without eating. Once I stopped taking it, the weight came off effortlessly. As for the shortness of breath, are you experiencing panic attacks? Or do feel it's something else. You should have your doctor take a look at you.
I can't be of help, except to say how sorry I am sorry about your loss.
You certainley have been through a lot. No wonder you are never hungry. You might be a little depressed which could cause you to lose your appetite. Have you considered antidepressants (or perhaps you are on them) to help you through all this, just until you heal from all your issues and loss. It doesn't have to be forever but just until you get through this stage of your life that is so stressful.
15 years ago I lost my mother and husband three months apart, among other issues, as well the start of my health decline due to all the stress. Stress can bring on health issues, or make them worse, or even bring on loss of appetite, or be the cause of not being able to lose weight.
Best to discuss your issues with your doctor.
Hang in there!