Hi Katykins
Sorry to read that you're feeling so unwell with a triple whammy of new HRT, flu and migraine - just one of those is enough to cope with.
I've never tried Tibolone, so can't comment I'm afraid - hopefully somebody will be along who uses it.
I had hideous migraines in my youth, which returned with a horrid vengeance when my periods stopped at 44 - on the upside, with the passing of time (I'm nearly 53) they have lessened somewhat. Battling meno plus added complication of migraine is not easy.
On the gel my migraines worsened too. The meno clinic advised that the patch would be better for consistency as for some women the gel can give too many peaks and troughs.
I am thinking that seeing as you're having an early-ish meno and have had endo plus migraines, maybe you could ask GP for a referral to a meno clinic. Often specialist treatment is necessary when other health issues are involved eg. migraine - my GP (at the time) admitted that the advice/care I needed was beyond her remit.
As we know, it's all trial and error and we're all so different - hope you settle on the Tibolone. If not, maybe try the patch/Utrogestan, if you haven't already?
Have you tried magnesium supplements, I find it does help relieve/lessen the migraines. I also use the spray as well on the neck knots.
Take it easy, hope you start to feel better soon.
Night_Owl
x