Welcome to the forum.
Anxiety can cause all sorts of physical and mental symptoms so it could be down to anxiety.
I am pleased that you have had some tests done and they have come back clear that is good news what I would say is don't google your symptoms as that will only make your anxiety 100 x worse trust me I have been there many times.
If it is anxiety lots can be done to help and a good place to start is our resources thread which you will find on the main page first post for some useful links to self help guides.
I try not to worry about the future -- so I take each day just one anxiety attack at a time.
ANXIETY & PANIC FORUM MODERATOR
Diagnosed with:- Asperger's Syndrome, Dyslexia, GAD, Social Anxiety Disorder, Health Anxiety, OCD, Depression and Scheuermann's Disease (Adult)
Medications:- 60mg Prozac, 30mg Mirtazapine , Haloperidol 2mg per day, Dihydrocodeine 180mg per day