Panic attacks are the worst hell, and they leave one feeling so empty and drained, as you described.
The more you can survive these bio-chemical onslaughts within yourself without resorting to alcohol or dugs the stronger you will be in not being at mercy to these acute adrenalin rushes - for this is what a panic attack is basically.
After I learned what they were physically, I slowly experienced more power in working through them without having to flee, and then to my present state of being able to catch the warning signs very early and to ward them off completely. I may still get the sensation that one is coming, but I have the tools now to breathe them away, relax my stomach muscles, and stop the attack.
By the way, the book that helped me so much has been re-issued, I see. If you are interested you might look for it at the library before buying it:
http://www.amazon.com/Panic-Attacks-Christine-Ingham/dp/0007106904/sr=8-9/qid=1169824474/ref=sr_1_9/002-4961411-6808811?ie=UTF8&s=booksOf all the books I read on the subject, this one "hit the spot" for me.
One of my most enlightening and powerful tools was to reach the point that when I felt it threatening - where before I would panic just at the thought of an attack, making it even worse and would try to escape the physical situation I was in - I gathered all my inner strength to challenge it, to even mock it to come and get me....it could not destroy me.....and was amazed at how this, after a bit of practice, worked to stop it in its tracks. (Along with regular, deeper breathing).
But you mentioned that it hit out of the blue, so maybe learning a few good breathing techniques to help you ride out attacks like these would be your best first aid help at this time.
But definitely try to find things to fill in your time that you used to spend in a more self-medicated state, things you enjoy, or used to enjoy...
Congratulations on taking such a big step out of your regular routine! I am sure that many here well understand how this feels.
This is a huge step, but as I mentioned above, taking baby steps along the way in other things is very effective too.
:hug:
DemEx