i thought the same as you do ,that i didnt have anxiety untill my heart started missing beats and i started feeling dizzy all the time ,my doctor said for me it was stress ,i thought she was crazy and went to another couple of doctors for their thoughts ,i finally went to a holistic dr (natural health doctor) she explain that even though i feel ok and not stressed that sometimes the body feels what the brain does not (its abit confusing i know ) but she told me to got to counciling and to relax more and feel positve ,it was a long road to take but i did it and the heart beat is normal again and i feel 100% sometimes it comes back a little bit but instead of worrying about it i use it as my stress monitor and get rid of whatever is stressing me out , try natural remedies ,stay away from chemical drugs in the long run they just make everything worse and  be kind to yourself,love youself, go to counciling ,learn more about the inner you and how you tick (so to speak ) i wish you the best