my hair looks thin anyway because of the way it’s cut, but it’s been feeling greasy recently after washing. any recommended shampoos?

my hair is naturally wavy, about 2b. i’m not losing any more hair than i usually do, but i feel like it’s looking weighed down and dull because it feels greasy even after washing. i think my hair is low porosity. i wash my hair once a week and use rosemary oil on my scalp, leaving it in for an hour before washing.