is what I have really anxiety or something else?

It's just, I'm kinda confused because I don't have a history of anxiety. I do have rapid cycling bipolar and adhd, but no history of anxiety/panic disorders, etc. However, all of a sudden, starting earlier this year, I began having what the doctors are saying are "panic attacks". I honestly thought I was having a heart attack, that I was going to die. And the thing was...nothing was wrong! I was getting my hair done for a wedding that I was attending and boom. Fear such as I'd never felt, palpitations, sweating, vomiting, numbness in limbs...I felt like I was dying, I was so terrified. I wasn't stressed at all beforehand, I was actually looking forward to going, was totally happy and carefree. Then that happened. I went to the urgent care down the road and they took an ekg and a chest x ray, my vitals, etc. Said I was fine and gave me xanax for "anxiety".

I'm not sure regular doctors (non-psychiatrists) should be fit to make that assessment, but whatever...

And I feel like there are other things going on like sinus problems, thyroid problems and carpal tunnel because my ears and eyes and nose are often stuffed and full of pressure and I get dizzy, my lymph nodes and throat are often swollen and sore and my fingers, wrists and elbows, as well as my actual arms hurt a lot and I do type on the computer/game a lot. So it's got me wondering if I have some physical stuff going on too or if I'm just freaking out over nothing and it's the so called anxiety causing it. I'm not saying anxiety isn't real...I'm just not sure that I have it...can it really pop out of nowhere with no history? What if I do have a bunch of other issues and I just don't know?

I want to sort this out, but I can't afford insurance and I've applied for the free insurance in my State but no dice...I really don't feel well most of the time...in addition to everything I just put up there, I also feel extremely tired a lot and get really bad headaches a lot...

I sometimes wonder what if it's a heart attack or something?

But then I get thinking...it's worse when I'm alone or scared...

idk...

Help?

I'd like to know what kind of symptoms you guys get when you have panic attacks so I can see if some of my stuff could be that or if it's some other stuff...also, any suggestions on medical care would be awesome...thanks.

I guess that's a relief that it's not something more serious...but can it seriously just come out of nowhere with no history or anything?