Hello and welcome!
You have come to the right place for support and understanding! There are many of us here who have had, or are currently struggling with this issue.
I myself found much help through CBT (therapy)...self-help, such as the links that I am going to post for you below...and of course the support of this community!
We are glad you have joined us. Keep posting...support is key!
Looking forward to getting to know you better. :)
Scaredy Cat
Books for overcoming Health Anxiety:
http://www.amazon.com/Overcoming-Health-Anxiety-David-Veale/dp/1845298241
http://www.amazon.com/Treating-Health-Anxiety-Cognitive-Behavioral-Approach/dp/1572309989
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