How old are you? Everything you describe is exactly what I've experienced for the last year. It got so bad that that I've had two full on attacks which were so bad, I was convinced I'd had a seizure. Saw GP and he told me it sounded like anxiety attacks brought up by the menopause. I KNEW it wasn't that. I didnt feel anxious and one of the attack happened on a day I was really looking forward to (and was totally ruined as had to go come back). I am not an anxious person by nature.
I therefore took over and persuaded him to do many tests, a number of blood tests beyond the standard ones, referral to ENT, referral to cardiologist, brain MRI... and all came back normal.
A year on, having done a lot fo soul searching, learning more about myself, doing some self-taught mindfulness exercises and cbt, I now know that GP's diagnosis a year ago was correct.
The surge and drops of hormones is messing about my nervous system. I am no anxious in that I don't get scared but I'm anxious by anticipation. I find myself feeling always wired up and unable to relax as if something in my brain refused to let me. I'm always rushing, analysing each situation, rehearsing potential future conversations over and over.
As a result, I also don't switch of at night and so it is a vicious circle. It took me months to realise how physically tense I was. It was various masseuse making huge 'OMG I havent had a client with so much knots in her upper back/neck for a long time' comments to realise that indeed, it's not just my mind but also my body that is all tensed up.
This constant state of anxiety is affecting my nervous system, giving me headaches and muscles pain, and impacting on my heart, in my case, getting it to slow down living me with very low BP.
So yes, anxiety, even if it doesn't feel like this can make you feel very unwell and I do think there are many people getting nowhere with the medical system who suffer the same but don't accept that it is anxiety related because this state of being is so ungrossed in them that saying so is challenging their whole self being.
Mindfulness and cbt is really the best medicine. I've embrassing it but it takes a long time to change years of bad habits and the hormones don't help but now that I know what it is and more importantly that it won't kill me, I don't get anxious at being anxious as I used to so it's a lot easier to live with on a day to day basis and I'm confident that I'll get to that stage where I can let go and enjoy life in the present rather than constantly trying to protect myself against a potential nefast future.