I did see a therapist for awhile, but that wasn't much help for the panic attacks - just kinda nice to have someone to talk to (even if their artificial interest did cost $100+/hr). However, most of my recovery from panic/anxiety was through my own search - a combination of life changes, as well a special form of meditation that I "created" for practicing being accepting/tolerant of the anxiety sensations. That has been the key to reversing panic for me. I'm not sure if it's right for everyone, but worked perfectly for my situation/personality. Let me know if you want to know any more about that.
As for feeling suicidal, "hopelessness" also made me think about suicide FREQUENTLY for years. But in the back of my mind, I never really had the intention of going through with it. As miserable as I was, I was still always more afraid of dying (in fact, isn't that the ultimate fear with panic attacks? that they'll kill us?).
However, I cannot say that my experience is directly comparable to yours. I think you mentioned depression. While I had a fair level of hopelessness and mild depression that one would expect while living with panic attacks, I was never diagnosed as having "depression". Typically it's major depression that's associated with risk of suicide.