I suspect you might be one of these people Dr Louise Newson talks about, who end up on a variety of drugs when all they really needed was the *right dose* of HRT.
If you're getting night sweats then you most definitely need HRT, that's a classic low E symptom. And it's extremely promising that your anxiety got better when you first started. But like many you probably need an increase and 75 might not be enough.
Have you had bloods done to see if you are absorbing it? That would be the first thing to try. Make sure any bloods are done during your period, so your own E is lowest and you will most clearly see what you're getting from the HRT.
The problem is that most GPs will tell you that bloods of 250pmol are lovely and you should be very happy and any remaining symptoms are not due to hormones. But they are wrong. Many women - especially younger women - need higher doses of estrogen because a lot of the symptoms are due to fluctuations and the higher doses 'buffer' the fluctuations during perimenopause.
I'm with Newson Health and my Newson doctor says that many women need E between 400-600pmol during peri-menopause for symptom resolution. HRT isn't really designed to give this kind of dose, for most women it gives a much lower dose around 250-350pmol.
For me, I need a high dose of E (I'm on 9 pumps of gel and about to increase to 10 pumps/day) to get me to just 450pmol - because I don't absorb it well. Which is all to say, since you don't know which direction to go, a blood test could really help if you do it during your period. If it isn't at least 450, try an increase.
From my own experience, I noticed zero improvement in many of my symptoms until I passed the magic threshold of 8 pumps of gel. There wasn't a gradual improvement as I gradually increased - nothing seemed to be happening and i was very dubious that this was estrogen related and that anything was going to get any better. But I'd explored lower doses and they hadn't helped so exploring higher doses was all I had left to do really. Things weren't getting worse, so I kept going up. At 8 pumps things got dramatically better. Even slightly better still at 9 pumps, but I'm not totally symptom-free yet so will be trying 10 pumps. (If I need even higher I will need to go to Sandrena or patches.)
The foggy head could be a progesterone side effect - what are you doing in terms of progesterone? But that is a lot of prescription drugs you are on, there, and the side effects of several of those include brain fog. Pregabalin is something I was prescribed but refused to take after reading the side effects and how difficult it can be to get off. Do experiment with stuff and you will eventually find what works for you - but it can take a while, this is a slow process!