Moved to the US

Hello!
I am Italian, and have been no poo for over a year. I tried a bunch of methods, and found that soapnuts worked really well for me.
I have low porosity hair, greasy on the scalp and dry on the ends.
In October I moved to the US, and since I got here my scalp flakes when I scratch. It's not dandruff, it's not itchy and it does not smell, the flakes are white and small, I just can feel, to the touch, my scalp being super dry. I added shikakai and arappu to my routine, hoping to get a bit more moisture, and my hair is actually amazing, but still flaky.
I tried an ACV rinse a couple of times, but it doesn't do much either.
I have also been having trouble digesting the food here, and I know that can change your scalp.
My question is: is it ever going to go back the way it was before? How long could it take to adjust? I'm in NYC, and even though the water is not harder than im Turin, the city I lived in before, the weather is much dryer.