My first one was when I was 7! I was a really sickly kid and so I had to stay home a lot of the time with my mom, and that year was the worst in terms of illness. When I would finally go back to school after weeks of being gone I would start freaking out, my stomach would hurt, and I wouldn't be able to breathe. Obviously I was still really young so I had no clue what was going on, but I know now that's what it was. I don't get them too often anymore, but the absolute most important thing you can do is BREATHE. Focus on your breathing the most, because it's the best way to prevent a panic attack from starting or to calm yourself down if it gets past the point of preventing it. Usually I try and repeat a mantra in my head while I take deep breaths because otherwise my thoughts will start racing, causing me to panic even harder. Mine is "I am okay, this is temporary, I will not die, I have done this before". You can say yours out loud or just repeat it in your head. Once the panic subsides, I try and drink some water. If the anxiety is passed, I take a little breather and take time to collect myself. If I'm still feeling anxious, I'll get to a place where I feel safe and listen to some music if I can. Personally I like to be alone if I'm panicking, so I try and get somewhere where I can do that. If you're more comfortable with a certain person to people, try to get to them. Just realize that not everyone knows how to deal with anxiety in the best way, but try not to take that to heart. I wish you the best of luck!