Hi ~ I used to have horrible attacks like that, and it drove me insane. My doctor put me on a beta blocker, PERIOD. That slowed down my heart rate, and it worked for a LONG time. The medication was Inderal.
I've also suffered from Depression since I was a small child but was in my 20's before I got treated, so if you're still suffering from depression, there are a lot of medications for that. It takes awhle before they start working tho. Some of them don't start working until you've been on them for about 6 weeks! Others, it can be as quickly as 2 weeks or so. Right now I'm on Cymbalta, and that has been working very well for quite some time.
Talk to your doctor about this. Perhaps just a beta blocker will help the panic & anxiety. I know you've tried it before, but you used it along with another medication. Try it alone and see if it works. It sure did with me.
I wish you the very best. Please take care & God bless. Hugs, Lee