Not offering medical advice in the slightest... I'm not a doctor and I don't know your situation, but Xanax got me past them (with a healthy dose of time, therapy, and lifestyle changes).
It took two years of taking the highest "probably not addictive" dosage, but my panic attacks ceased almost immediately after starting it and once I decided I was ready I was able to cease it altogether.
I'm still not healthy, but I can say I went from a panic attack every day or three to not having had one in three years and being off-meds for four months.
Anyhow, something to think about if you haven't explored that route already. If you have, good luck.