Sudden seborrheic dermatitis

Hope this is relevant as it’s skincare adjacent!

After 37 years of a healthy scalp, I started developing moderate seborrheic dermatitis with dandruff out of nowhere. It’s exclusively around my hairline and a bit flakey and irritated. I got an RX shampoo from my derm, and am planning to schedule a follow-up appointment, but in the meantime, the problem is on,y getting worse. Wondering if others out there have products/treatments you can recommend, or can share how you eventually got the dandruff under control!

Thanks in advance!