Dry Scalp - please help!

For about 2 years now, I've been washing my hair around once a week. It has done absolute wonders for my hair. I also let it air dry after being washed and I do not use any heating tools. All was fine until a month ago. My scalp has become a nest for dandruff and its disgusting and embarrassing. I have very long hair and it is frustrating and tedious to slab hot oil and honey all over. I tried it for the first time last week. I applied it all over my scalp and let it sit in a couple microfiber towels overnight. It was messy but it helped. Unfortunately, I am back to itching. Any other, clean ideas?? Thanks!