Don't worry, Em Dee. Panic attacks are horrible but I promise they can get better - the key thing to remember is that you aren't in any danger or about to have a heart attack etc. the first time I had one I thought I was going to die, my body was paralysed and I thought I couldn't breathe. I got them every few days for a few weeks afterwards, but as soon as I worked out I wasn't in any pain/danger etc they got easier. Within a week I was able to keep playing a game of poker while having one! I haven't had one for years but don't mind now if I get one, it's just a wiring problem in your brain-to-body relationship but not one that can harm you.
If it helps I've also had a viral heart infection which mimicked heart attack symptoms! Am still standing and more than twice your age - you'll be fine