I'm having this issue, and been having it every month at day 14 and day 28 for nearly ten years (since they took my thyroid out), and then in the 12 days I was on estrogel it went off the charts (last day resting heart rate 120, and my face and lips went numb, and my entire body was shaking, including my vision!!). Suffice to say I stopped, but still trembling like a leaf days later.
I'm fairly certain it's estrogen mediated mast cell over activation, and it seems I'm not alone, lots of women get this. For me it's caused by, I am fairly sure, peri surges of estrogen.
It's also connected to methylation in ways I don't understand but estrogen is a methyl donor (as is betaine, stomach acid), and the biochemical pathways are too complex for me, but this is connected to methylhistamine. I have that MTHFR defect which means I have issues tolerating certain B vits and folate.
All the other women I'm talking to about this also have thyroid issues. I'm due to speak to my func med doc, as she think she knows what's happening, so once I know I'll report back. I'm also due to speak to an immunology clinic, as these are the symptoms that prompted me to seek gynae help in the first place, as they are so cyclical it HAS to be my sex hormones.
However, I can confidently say I have NEVER felt so ill as I did taking estrogen, and it does beg teh question why my gynae gave it to me when my blood tests said my E was 300 points over the top of the range at nearly 1,600!!! I appreciate that hormones swing in peri, but I find it hard to believe that doctors haven't come across this before.