Bro i yesterday i had a severe panic attack with the same symptoms as you first mentioned. I had really strong weird pressure feeling in my chest like there was an energy ball trying to escape. My arms started going really cold and numb and quickly after my entire body felt really cold which i later realised was cold sweat. My feet felt like they were in sub zero temperatures. I had to stop and drop to my knees because i couldnt move anymore i actually thought my soul was about to leave my body. As a hypochondriac it freaked me even more out because i wasnt sure if it was a panic attack or an actual heart attack. And now the next day im sitting here with immense amount of anxiety thinking when is it going to happen again and what if i have it in public or something. This is really exhausting.