Choices of foods, may become important if you have intolerances.
Hot sauces, salsas, lots of tomatoes are not tolerable for some people (including me) because they increase burning nerve pain.

If this is true for you, then you will have to avoid them. Do an elimination diet of them for 2 weeks and see what happens. If you improve, then when you use hot sauce again, you get a flare, that will be your answer.

I try to follow the Zone diet. It has shown good response for sugar control, and has been around a long time. It is moderate and allows you to eat rather normally with just some balancing of types of carbs/protein/ good fats.

Do an elimination of gluten, this same way, and dairy to see if you have some intolerance to them too. Do the eliminations one at a time, for clarity.

If you don't have a gluten problem, you can have some breads in moderation. I'd avoid ice cream, and high sugar loads though.

You can switch to another eating plan in a month or so if Zone doesn't agree with you. One thing I'd be careful of is eating junk food. Eating MSG in that junk food also.

There is new research suggesting junk fast food actually causes autoimmune diseases...
http://neurotalk.psychcentral.com/thread230822.html
autoimmune diseases, lead to neuropathies.

Learning to make simple meals can be done at home. Just watch for MSG in processed foods (Doritos, some soups, etc).

You will get the hang of it.

I suspect your sudden weight loss is water weight. That will stop in a week or so, as you plateau out.

I am sure others here will give you advice too. So keep your mind open to ideas, and choose what will work for you.