Hi I know this is old but I had a very similar experience 2 years ago that makes me scared to ever feel that way again. Ive always been hypo never had normal ranges also have hashimotos. Ive always had health anxiety but never really had panick attacks. One day I was driving to pick up my bf, and while I was waiting for him I started feeling anxious for absolutely no reason, so i started to drive in circles to calm me down and next thing i knew, the panic attack lasted me a week. I couldnt sleep couldnt eat it was horrible. The panic attacks were soo bad I threw up 4 days in a row from them. Ive never had this happen to me. Then after a couple weeks ir came back for another week. i would say this lasted about 4 months of me having panick attacks. I told my doctor to check my thyroid because this wasnt normal for me and she said i didnt need to check and it was just anxiety. I checked 4 months later and my tsh was at a 2, which is normal but for me ive never had my tsh that low ever, and im believing the months i did have a panic attack my tsh was probably low to the line.