Kathleen, I'm so sorry to hear that, you really do seem to be struggling to find the right combination of medication.
The Pregabalin sounds well worth it try. It's on the list of migraine preventatives my specialist recommends but I haven't tried it yet because I'm convinced I just need to increase my oestrogen dose which is working very well so far.
I'm 63, am I right in thinking we are a similar age? I made the classic mistake of thinking that because I am about 15 years post menopause I had bottomed out, everything would settle down and I could just keep going on one pump of Oestrogel forever but I was wrong. It turned out that one pump was not enough and it caused my migraines to resurface. Is it possible you could be in a similar situation? My oestrogen blood levels were about 270 pmol which I thought was an acceptable maintenance dose but apparently not. According to Bombshell on here, it's rock bottom.
If the Pregabalin doesn't cut through, I really think you need a complete rethink on your medication because there seems to be a missing link. Low oestrogen has a profound affect on the brain and in my case it's migraines but in your case it's mood swings and anxiety. In other words, it's probably the same cause (lack of serotonin, dopamine etc) with a different manifestation. Very often just increasing your oestrogen is not enough and you have to add in other medication but it's got to be the right type at the right dose. Just getting one part of your medication wrong can throw everything off course.
What is your current blood oestrogen level? Is your blood pressure stable because that can't affect the brain. There is so much to unravel and it's complex stuff.
I hope that gives you some ideas