I've just quickly looked at your post history. This stood out for me: 'For the last couple of months I’ve noticed huge heart rate spikes when doing very moderate exercise eg. Just walking to work. At times it’s registered 200bpm on my Fitbit.' I'm a super anxious person, who wears a Fitbit, and that would really freak me out.
So here's what I think is happening. You noticed something irregular. No one has been able to give you an answer. You feel as if you're being palmed off with 'Everything's fine' when you believe that it isn't. This is increasing your anxiety. You're refusing to accept the old hysterical woman / hypochondriac label. Alongside this, you seem to be perimenopausal and I can't work out whether you've decided to try HRT or not.
But the cherry on the cake is that you can't sleep and you're completely exhausted.
The rational part of me would consider breaking this down into chunkable steps so that it's not an overwhelming mass of chaotic panic.
1. You need to sleep, speak to your GP, Mirtazepine is frequently prescribed. If you don't fancy that, maybe try some Kalms Night (however, it's Valerian, so don't take it for more than a couple of weeks, ask your pharmacist).
2. What did they say about the heart rate thing? When I was in peri I ended up at a scheduled ECG - referred by GP. This helped to ease my mind. However, I also had to change another medication (for blood pressure) that was causing issues.
3. I get a sense of tightness in my chest, always related to how much cheese and meat I've been eating. Switched to a Mindful Chef vegan / gluten free meal box 3 x weekly and this made the worrying sensation disappear. It came back over xmas when I cancelled said meal boxes and ate a lot of rich food.
4. I take D3 and K2 (combined, made by Viridian) every day. Noticeable uptick in stamina. I also take Floradix iron and vitamin tablets when I'm feeling a bit run down. I'm a teacher. Sometimes even my tired is tired but these two steps seem to sort me out - the 30 year olds I work with don't know where I get my energy from.
5. Related to points 3 and 4, I eat a high protein diet. Often start the day with a Fuel protein shake, followed up with Fage 0% fat yoghurt + blueberries, then a banana, oat cakes, ridiculous amounts of pulses.
6. I also smoke a vape and drink bourbon, not a nun.
7. I see a massage therapist and a herbalist as and when needed.
8. I've been married a long time, my husband is a decent guy.
9. I've been in weekly f2f therapy for 6+ years.
10. Feels like there should be a point 10.
For me, peri was a process. I didn't have any of the above in place when I was going through it. Horrible, horrible time. Thought I was dying and no one, except me, was willing to accept there was this massive thing that was wrong. It was invisible, haunted me, my own personal demon in my own personal prison. It's like I was locked in there. Totally isolating. I tried HRT and it caused my blood pressure to spike, or those two things happened at the same time, whatever, my GP withdrew HRT. I just had to work through it, one thing at a time, and find reassurance where I could. To be honest, the women who treated me with massage, herbs and psychotherapy were really important to my survival - because they listened. The vit D3 and K2, together with the multi vits, helped with stamina. The Kalms (and herbal remedies) helped with sleep.
Don't doubt yourself, find what works for you. You'll come out the other end of this stronger and really quite sure of who you are.