Spadgar, if I was a gambling person, I would put money on the fact that your problems are because of the progesterone content of your HRT. Continuous combined HRT is a great idea on paper because obviously it is a bleed free preparation and nobody really wants to have periods but unfortunately it comes at a price and that price is the progesterone cancels out all the good work that the oestrogen does.
It's the same old story and I had exactly the same problem when I was on a continous combined regime (same dose as yours). It all started off well and but after a couple of months, the progesterone built up in my system and it stopped working. Realising what had happened, I then topped up the oestrogen by bunging on an oestrogen patch and that made it just about passable but it was still nothing to write home about. I still had constant breast discomfort (something I only ever get with progesterone), digestion problems, low mood and was left feeling half baked and not quite there.
My advice would be to switch to another product if things don't improve. I now use Oestrogen/Utrogestan and it is the best HRT regime I have used by a very long way. It does mean having periods again but it is a small price to pay for feeling normal again. Oestrogel/Mirena coil is another option but its success would depend on whether or not you are progesterone intolerant. I am severely intolerant to all synthetic progesterone and high doses of Utrogestan so I have to limit its use.