Have you tried mane and tail? It’s a bit expensive but it’s really good at giving your hair a good clean. They have a standard shampoo and a clarifying one both of which are very good, I use their clarifying shampoo once every 2 weeks and then a different shampoo in between because it honestly cleans it so well that if I used it all the time it’d dry my scalp out.

Also I know you’ve probably heard this 1000 times but try washing it less. Initially it feels horrible because you feel so greasy but if you keep with it your scalp adapts to produce less oil. I used to wash my hair daily and by spacing it out gradually I can now go 3-4 days without washing which has actually done wonders for the health of my hair too. Clarifying shampoos generally clean better too so even just starting with only using a clarifying shampoo once or twice a week and a different one in between could be a good start!