dut can take a while to really kick in, like 12–18 months. For the oily scalp, something like ketoconazole or a salicylic acid shampoo could help with the oiliness and inflammation, which might also help slow the shedding. PRP is considered ineffective around here. Have you thought about microneedling?
Read the beginner’s guide and this great post on Dutasteride dosing