OMG- You sound like a carbon copy of me!! LOL
I have exeactly the same thing at exactly the same time!!!
Been going on now for about 18 months - sorry to be bearer of that news.
I started HRT April 18, Femeston 1mgs, within 3 days, relief- i couldn't belive it, all stopped- so obviously hormonal.
Then they came back in the july , so upped to femeston 2mgs- again stopped until october, then bingo back again.
So now on patches- 50mcgs- I was sooooo fed up, but my Oestrgen was 1164!!!, Go says mm bit high
BUT being the naughty 'experimenter' that i am, I have out 2 on to see what woudl happen- and 3 days later i slept all night- it is soo obviously hormonal or it woudl not stop at all. But what gets me is that it is so unpredicatably predictable (if that makes sense)
I am hoping that it won't come back
But i like you are totally at a loss to explain why i get no flushes at all at any other time- just this one, at the worst time. I wake up drenched regardless of environment.
Most of my other symptoms seem to creep back too- 'can't be bothered' feeling, insommnia and wee wakes and then go when i up the dose
I too would really like to know what on earth is going on.