Hi BTurc and welcome!
I am sorry to hear of your anxiety challenges. It is scary and confusing to go through all that you described. I am glad however to hear that you are pro-active in your recovery goals, and will be getting into therapy soon. I believe wholeheartedly that this will help you!
For now, we have some great free and accessible Resources that I would like to recommend to you.:) There is great information, as well as self-help techniques to be learned for anxiety management. They are really effective if practiced everyaday.
https://www.healingwell.com/community/default.aspx?f=9&m=104206
There is even a whole list of materials for health anxiety to read up on and put into practice.
Check this out, and see if you find it helpful for you. Keep posting as well...support in and of itself is healing...and we are always here to understand and listen.:)
Talk to you soon,
Scaredy Cat
(and to answer the brain's chemistry question, yes, anxiety can affect our brain's neurotranmitters/hormones, ect...but therapy and self-help can reverse this affect, so great job on getting started!)