Dandruff, dry scalp, HELP

Guys, how the HELL do you get rid of a dry flaky scalp 😭 any product recommendations? I’ve tried EVERYTHING. Apple cider vinegar, tea tree oil in my shampoo, using a scalp scrubber, conditioner on the scalp every couple washes, putting aloe vera on after a shower. It WONT go away and I’m so insecure about it. It’s not a lot but it’s definitely noticeable, and my hair dresser points it out every time she does my hair😔 my head also gets really itchy through out the day. I don’t know what I’m doing wrong :(

Edit: *I also only wash my hair every 3 days, so I don’t think it could be from over-washing. I moved into a new apartment and the water there isn’t the best so that could be a factor but I’ve had this issue longer than ive lived there.