Hi ZT and welcome!
I am sorry to hear of your current struggles.:(
As you can see, you are not alone! You will find many people here share the same challenges with their anxiety and similar symptoms.
What if anything have you done yet to manage your anxiety? Talking with your doctor for treament options would be a good place to start if you've not done so yet. You can discuss medication and or therapy.
For now, here is the link to our Resources. You'll find all kinds of great sefl-help ideas...including the breathing exercises that you mentioned. They can make a difference if practiced daily as part of a discipline!
https://www.healingwell.com/community/default.aspx?f=9&m=104206
Here also are some good links specifically for help with health anxiety. It will be worth your while to check these out!
Health Anxiety - A Self Help Guide:
http://www.nhs.uk/conditions/hypochondria/pages/introduction.aspx
Helping health Anxiety
http://www.cci.health.wa.gov.au/resources/infopax.cfm?Info_id=53
Health Anxiety- The Super Scanner
http://www.get.gg/docs/SuperScanner.pdf
Keep posting with us if you find it helpful. We care, understand and support is key!
Scaredy Cat