Welcome fedmae!
Lucky you- I have been to Seattle and found it a great place to be.
Who makes the meals in your home? Can you maybe sit down and address your health concerns with them? Maybe make up a list of healthy snacks you would like included on the grocery list would help and if you volunteer to help with the meal planning and cooking?
If you don't want to be on a "diet" you can try lifestyle changes by slowly incorporating more fruit and vegetables into your life, eating less fatty and fried foods and limiting the amount of junk food and fast food you eat. To me this is just adopting healthy eating habits rather than a restrictive diet. This is sometimes a better way of doing things for some people.
You are off to a good start by going walking - great form of exercise!
Checking with your doctor is a good idea - you can get an idea of what your general health is and they can advise you on what kind of eating habits are suitable and what type of exercise you are able to do.
Check out the rest of the forum- there is all kinds of support and ideas available here.
Good luck