my first experience with panic attack

I was at work getting report from the charge nurse. i was sitting at the nurse's station feeling uneasy and sick to my stomach. before this, i was doing my regular things that i do before coming in to work. all of a sudden, right in the middle of shift change, i was feeling very uneasy, palpitations and dizziness. i had my co-worker (RN), checked my pulse for me because they felt like my heart was racing. And it was, when she told me how fast they were I just started flipping out and got very nervous and dizzy. i thought i was going to passed out and have a heart attack. Right away, they put me in the wheelchair and took me to the ER. They run some tests and of course they were negative. At first, they thought i had a "thyroid attack", where your levels are high caused you to have tachycardia etc. But at the time while I was in the ER, i was having this empending doom feeling that i was having a heart attack and a lot of things ran through my mine like i just want to have a chance to be a mother, i don't want to die yet. I never felt to scared in my life. After this happen, weeks and weeks i was feeling very anxious, restless, started avoiding things i used to do. I went to see a psychologist few weeks later after my first episode and was told it was anxiety that i had a panic attack. It definitely made me feel a little better that it was not threatening. however, having the experience of panic attack definitely felt like i was going to die. from then on, my life has changed completely. i do wish to have my life back to what it was but at the same time i would not know what changes i would have made now if i did not experience this.