Hi there,deep breaths girl.Anxiety is the pits and sadly one of the worse effects of meno in my opinion,the early hours are usually the worst,surges of adrenaline make you feel this way. I don't know much about HRT but it sounds like you need it tweaking and should go back to your Dr. When I get these awful episodes, I do breathing exercises,whilst tapping on my chest/legs/wherever with my hands,breathing in for four and out for four,this of course won't cure you but might help until you see someone.
Have you tried CBD? Also a few of us on here are great advocates in Vit D,this has helped me greatly,takes a few weeks to get into your system but worth a try. You'll get there,you're definitely not alone on here xx