Anxiety disorders: physical illness or mental condition?

I have suffered from anxiety and panic attacks for five years now. In every other respect I am a healthy, confident and reasonably contented individual. Nothing in particular causes them and I've tried CBT, anti-depressants, exercise and diet.
My question is: Is my anxiety a result of "incorrect thinking" or is it a physical thing like a broken leg? It can't be both. (Obviously the effects of the anxiety are physical, but I'm talking about the root cause).
If it is purely as a result of my wrong thought, then the only cure is correcting the bad thinking myself. If it is physical, like cancer, then it needs medication: as no amount of positive thinking will fix cancer: it needs drug treatment.
Do you see my point?
Any thoughts?

If you wanna get technical yes it's probably mental.. I fight with myself every day to go out and be social, it's such a hard thing for me to do. I get so anxious around people I do not know, even those who I might know sometimes.. it can spill over to physical though if you stress and worry and focus too much on the anxiety itself.. I've given myself anxiety attacks because I sat and worried and wondered about things that I probably should have just let go in the first place. If you can 'correct the bad thinking' on your own then more power to you.. I just couldn't seem to do it, I don't know why it was so hard but it still is to this day. I've actually recently been given trial bottles of Cymbalta and I'm not having too good of a reaction to it right now.. woke up at 3 am and sick as a dog at my stomach, no vomiting yet thank god but I managed to eat some toast and I think it might have helped. If it were up to me I'd just go med free and try to do this alone or with the help of a psychiatrist or someone I could speak freely to without feeling so looked down upon or judged. Unfortunately I don't think I could feel comfortable enough with anyone to talk with in this way.. and it's probably because of my 'incorrect thinking'. It's almost a catch 22 the way I see it.. I want to fix things.. but I almost feel I cannot trust people with my feelings for fear of rejection or to be thought of badly, etc... I think maybe with the right medication anyone with anxiety could have some relief from the symptoms they struggle with every day but if anyone who has ever suffered with anxiety disorders has the same problem as me.. it's just very hard to open up and be so trusting. I could be completely off base but that's just my $0.02. Hoping you have good luck with dealing with your anxieties in the future.. it's rough stuff, just know you're not alone when suffering with these problems. Best wishes.. take care.

Whoever said a physical condition and a mental condition were diametrically opposed? The brain IS part of the body, is it not?

My Mom suffered from terrible Generalized Anxiety Disorder all her life, but was otherwise a delightful, funny, self-educated world traveling photographer. No amount of talk therapy helped. She took medication, which helped.

The Diagnostic Statistical Manual of Mental Disorders, Fourth ED. Revised, the manual psychiatrists and psychologists use to diagnose mental conditions and personality disorders, lists 13 main types of Anxiety Disorders, with many substrata listed. You probably have Generalized Anxiety Disorder, but it would be best for you to connect with a psychiatrist in order to be diagnosed so he/she can put you on the right medication.

Don't feel stigmatized by having a mental disorder--zillions of us out here have them, present company included (bipolar). The absolute best of luck to you, and Godspeed.

generally, anxiety disorders are a mental issue, but depends on how severe you are too. From what I understand medication is usually the cure, or at least helps. If you are feeling bad about yourself for any reason, that can bring it on too, it can be a mixture, but I would suggest more mental!
hope this makes some sort of sense.