Hi there GetStuffed peri! I don't know what you want me to say?
The point is if you are peri-menopausal then your hormones will be doing their own thing surging up and down and now and again you will ovulate so progesterone will surge and fall too as well as the oestrogen. There is no way of knowing exactly what is the cause and especially as there is a lag (eg between fall in progesterone and some symptoms)
You could try keeping a daily diary of your symptoms and the days of your cycle, bleeds etc to see if there is a pattern. Also keep a diary of what you eat and exercise and see if this related to your symptoms.
It may not simply be a question of oestrogen or progesterone anyway. For example have you had a thyroid test recently? What about blood sugar (you mention thirst)? Are you overweight at all? What is your diet like ie what sorts of foods comprise most of your intake? Could be all sorts going on.
A high libido will be a sign of high oestrogen and possibly testosterone and should be highest around the time of ovulation , although probably goes up the creek a bit at peri-menopause!
Low libido will mean lower oestrogen and if you have ovulated, then could be progesterone which also dampens libido and has a sedative effect (which some find calming in small doses but some find depressing in large doses taken as part of HRT).
If you had a look at one of the videos KittyKat put up, the um ghastly woman (!) does explain what is going on in the normal menstrual cycle. (I couldn't bear her! with her drawling slow American accent, silly pink gloves, and a bookshelf full of a million shoes behind her whaaat?).
It's all a red herring the oestrogen dominance thing just as Perinowpost says. Also like the pink lacy gloves woman said - it was dreamed up by the so-called "alternative" movement as a condition to sell progesterone-based products which could be made and sold without needing licenses ( not sure how it works in US).
Depending on your age you could regulate your cycle with one of the modern COC pills which is a bit like HRT so would prevent all those extremes, or take regular HRT which would prevent oestrogen crashes and regulate bleeding back to monthly.
Firstly though I would ask for some blood tests ( difficult at the moment) just to check there isn't another endocrine explanation for your symptoms, especially the thirst and insatiable appetite.
Hope this helps but has probably skated around your question....
Hurdity x
PS I'm not an expert on this but I like to give an opinion if I have one