You may be deficient in vitamins/minerals. Deficiencies can cause so many symptoms.
Get blood work for Vitamin D, magnesium, B12:
25 OH Vitamin D
Magnesium RBC
Serum B12
HotoTC levels
MMA
Homocystein
Anxiety can manifest itself in a bunch of different ways, many of which seem neurological such as you describe. If you haven't seen a doctor, you should just to rule out anything of a physical nature. But it's probably anxiety -- specifically, social anxiety and/or agoraphobia. Assuming the doc says you're physically OK (which you probably are), I encourage you to see a therapist and get cognitive behavioral therapy (CBT). You're the victim of "stinking thinking" and you need to get the way you look at things sorted out. I wish you all the best!