As you mention your diarrhoea has got worse recently, I wonder whether it's possible that some of your symptoms are related to this. Could you be dehydrated from the loss of fluid do you think? Does the morning hangover feeling ease when you've had a good amount to drink?
The weakness & dizziness also make me wonder about nutritional deficiencies - if 6 months since you were tested for these and bowels have got looser since then, I wonder whether you might now have poor absorption. I understand completely your reluctance to go back to your GP, but perhaps have a think about whether the diarrhoea might be at the bottom of this (sorry for the pun!) Are food intolerances a possible cause of the looseness, or perhaps dysbiosis (especially if you have had repeated courses of antibiotics)? Even if as you say, diarrhoea has been the norm for you for years, a recent worsening would make me question whether this could be affecting your general health.
Not sure what to think about the change of progesterone - but I wouldn't think this would account for the worsened diarrhoea, though prog does some funny things (most of them not funny-ha-ha) so I wouldn't rule anything out. I believe progesterone is more often associated with constipation & my gynae chose not to prescribe Utrogestan for me as part of my initial HRT regime for just that reason. The muscle relaxant effect is supposed to inhibit peristalsis, slowing passage of food.
I hope you manage to work out what's going on, but please do think about seeing a GP about the bowel changes - perhaps see if you can get an appt. with the one you feel most comfortable with. You really don't want to be losing too much fluid or having absorption problems.