I had panic disorder for at least 10 years. Between the ages of 16-25ish.
What worked best for me is a simple medicine called "inderal". It's not addictive like xanax / valium and is far more effective imo.
When I had to give speeches in college I'd start shaking, hyperventilating, my head, neck, face would twitch real bad then my heart would beat so fast I couldn't WALK OR TALK at all. I remember so many times just going to class I'd start stumble walking like I was drunk. Then I would feel my heart rev'n up and I knew I had like 5-10 seconds before it started. So I'd try to hide anywhere I could. In an empty stairway. Behind a wall or building. And I'd just let the panic attacks pass. The downside is many times this happened in public and it's the most humiliating experience in the world. Then you anchor that experience in your brain which triggers them more and more.
Inderal works by shutting down your adrenal system. When panic attacks occur, your adrenals trigger norepinephrine (adrenaline) in large loads, then your brain overresponds to the adrenaline which triggers more adrenaline and it just spirals out of control.
I actually told my college counselor "I can't graduate" cause I refused to take a critical discourse (public speech) class. And I had seen so many doctors and shrinks prior to this. But she told me about inderal and I couldn't believe how effective it was. I remember the first time I gave a speech I was able to speak clear and confident and be myself. Then class ended that day and I cried the whole ride home cause I was that happy.
The only reason the panic attacks continued after college was cause I only took the medicine on an as needed basis. But a few years passed by and my brain began to associate "this isn't a problem anymore, this medicine works, I don't need to be that scared" and soon enough they just stopped on their own.
Please try inderal. At least 20-40mg instant release.