First of all, your numbers look pretty close to a normal's to me. Your body appears to be able to handle a carb load in a reasonable amount of time. Also, there are lots of factors that go into testing that you may not be aware of... simple things like not washing your hands and test strips that have been exposed to humidity can throw a monkey wrench into the mix. A blood draw by a lab would be a good way to figure out where you are on the diagnosis.
I understand your fears about being turned down for insurance... We presently are without it. After a while you simply learn to take care of yourself and pray for the best. Even so, in most states you are insurable if you have been insured previously. Insurers like blue cross will accept everyone, but your rates may be quite high.
As far as the food plan goes, you could start following a 1200-1500 calorie reasonable plan utilizing lots of veggies and very little white carbs (bread, white rice, pasta, potatoes), lean meats and lots of good fats like olive oil, avacadoes, peanuts and other good nuts. Veggies, brown rice, barley and bran along with good fats will level out sugar and time release the carbs into your blood stream. Continue on your walking and you should be able to lose some more weight. That alone will help fend off the diabetes diagnosis. I wish you good luck, and until you get a lab blood test, you're a normal.
"People are like stained glass windows: They sparkle and shine when the sun's out, but when the darkness sets in, their true beauty is revealed only if there is light within."
- Elizabeth Kubler-Ross