I went through the same thing with my anxiety. I went to the doctor thinking I had asthma, but I was fine. If your doctor says you're healthy then there's really no reason to be taking medication. Therapy might not be a bad option. One of the key differences between panic attacks and anxiety attacks are the catalyst to the attack - for panic attacks, it's typically psychosomatic/internal trigger or the fear of having a panic attack/the physical symptoms you experience during an attack; for anxiety attacks, it's typically an external stressor - maybe an upcoming event that has been stressing you out, an exam, a deadline - something of that nature.

The reason therapy could be helpful is because you can learn to control your physical symptoms. When I went into therapy for my anxiety I learned several strategies to help reduce acute anxiety attacks. I learned diaphragmatic breathing to help my physical symptoms and I also learned to recognize the false beliefs I had and how to combat them effectively.

You don't have to go into therapy knowing why it will help; you just have to go into therapy with an open mind and a desire to help yourself - that's all. Don't tell yourself it's dumb or not helping from the get-go, just go with it and give it a chance. You may surprise yourself...