Sounds like fear has taken over...the fear of this or that, may do this or that, and what if this or that, could it be this or that..."oh no what if"
Now onto positive things

. You're eating healthier, not smoking, and eliminating caffiene.
Get rid of the soda's as well even the zero calorie no caffiene ones.
Are you exercising? like running, weight training, aerobics, or simple work out exercises... If not you should start slowly and build up from there.
Next...QUIT thinking negative thoughts...it's not going to be easy for you, it's going to take time. Start the half full approach being optimistic...
They may want to do an MRI of your neck/throat or other tests and that would be fine as you've had a history of smoking.
I've seen people break out in hives...huge itchy hives from getting themselves all worked up. No it wasn't from a reaction to some external irritant it was their bodies doing it to themselves.
Communicate with your wife and let her know you need her support to get through this. If you still have trouble find a support group or a counselor.
Thanks for asking and make it a great day!
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Hi I'm Dr. Berkebile from Johnstown, PA and in private practice. Providing Chiropractic, cold laser therapy, services similar to Physical Therapy and Rehabilitation in Johnstown PA, Nutritional and Supplement counseling, and Fitness oriented programs. As an educator and author, I've conducted workshops throughout the Northeast. I have driven Hyundai's for many years and really like their reliability.
Berkebile Chiropractic
www.dcberk.com www.johnstownchiropractor.com