I know one of the best ways to treat anxiety is CBT and exposure. The idea behind exposure being exposing yourself to what causes you anxiety, riding it out, seeing it isn't so bad, and learning that there's no reason to be anxious and ultimately recover.  


The problem is that I can't just ride it out. For example, I somewhat recently went to a little going away party for some family that way going to be moving out of state, and during that I had severe and long lasting anxiety. My heart rate, which is usually in the low 60s, was over 100 for about 5 hours straight, even though I was sitting the whole time. Combined with this I was also usually pretty aggressively bouncing my legs, fidgeting, and shaking, sweating, and occasionally messed up breathing. The only reason I started to not be as anxious was because towards the end of the night, where I genuinely starting to become to physically exhausted to keep it going. Of course, when I left it went away pretty much almost instantly. This is only one example, but the majority of the times I'm anxious it usually lasts for hours upon hours of end.  


But overall, the problem remains that the usual advice of "You can't  be anxious forever, you'll have to calm down eventually" is that I absolutely can be, ending only when I finally leave (which is essentially avoidance and running away. which doesn't help towards getting better).   


  
Furthermore, probably the biggest source of my anxiety, is anxiety. I largely get anxious because I believe going and doing this thing will provoke crippling and hellish anxiety. And when I go do that thing, it provokes the anxiety. It's hard to try and analyze cognitive distortions, or do the negative thought worksheets because it feels like it amounts to:  


I'm afraid to touch the stove because it will burn me. I touched the stove and I got burned. My fear, despite essentially being some paradoxical loop reinforcing itself and originating from nothing, has been completely confirmed, and my anxieties even further reinforced. Even worse is knowing that the answer is apparently "keep touching the stove and eventually it'll stop burning", but I've been touching the stove for years and years now and it still burns.  


Anyone have any experience or advice for very long lasting anxiety attacks or anxiety caused by anxiety?