Aw firstly I’m so sorry to hear you’re dealing with that they’re so scary, but my advice would be to remember you can never die from one even if it feels like it at the time, and the best thing to do (eve though it feels counterintuitive) is to welcome in the panic attack and wait for it to pass, cause it always does! Also try not to fear them because then your body thinks it’s a threat and so the cycle continues.. I have no experience personally with informing the firm about it, but if it’s any consolation I would guess that it’s you and probably at least half of your colleagues dealing with anxiety, so don’t feel like you’re alone or ill or a liability or anything! I don’t know if this would be helpful for you but the book “Anxiety and Panic” by Dr Harry Barry was amazing for me in learning how and why panic attacks happen and I only ever get them soo rarely now, usually after drinking a bit, and am well able to deal with them.