I had panic attacks since age 12 or so... managed them myself... then had a bit of a mega do aged 21. Rocking behind my boyf's bed. It was terrible. but it sounds similar.
Unfortunately, my GP at the time was appalling (long story, won't bother you now with that!) so I hid it some more. Aged 25 I had another do of it, and I was referred to our mental health department by a better GP!
After I received some counselling, I felt much better. It turns out, I'm normal!! Who'd a thunk it hey??!! Other people have ishoos too... even some have the SAME issues as me... I'm not a lonely weirdo that "no one will ever understand"
It's sometimes a matter of just writing a list of things that are bugging you, and seeing what you can do to start sorting through. Even just a tiny tiny thing can make a kassive difference.
I'm now 32, with a pip on the way, house and DP... Can't really say I love my job, but it's serving a purpose, and I have some ambition to move on once I'm settled after the pip is out 
We all make choices that sometimes are "wrong".... but that's OK. We can make new choices.
Would it be worth having a word with your GP, see if they can recommend someone for you to talk to?!
I've not had a panic attack since my therapy... felt close a couple of times, but had a little talk to myself, going over some of the points from therapy... and it kind of clicks back into "normal" again.
It helped that I went to therapy with an open mind too... I had no idea what to expect in there, or what I could take from it. I'm glad I went. I wish I'd gone sooner!!
Good luck