Why are they wanting to give you meds when they have no diagnosis. I have had panic attacks like that and they do come on out of nowhere. frightning... I suggest second opinion
. and why for life...? what arent they telling you? Go for nice long walks in the eve. get more sleep. and try to relax something is bothering you wheather you realize it or not.
I would ask for a MRI
if you are that concerned just for peace of mind.
I hope you feel better.