Then seek professional mental help to deal with not accepting your negative test results.
I have not any symptoms, but i am very anxious that it will change positve at one day. So I live with great horror everyday. I can not control myself.......
You may wish to visit the anxiety forum, however some interim tips are:
Keep your self-distracted
Do not go searching through the Internet for symptoms
Remember your own brain creates anxiety so in the end you control it and can overcome it!
That part is up to you. I wish you well.