I used to have this issue. What I did was wait until extended holidays (Easter, Summer etc) where I wouldn’t have to go out every single day, and then literally leave my hair unwashed for 4-5 days, even if it turned into a grease pit.
This worked best during summer because I had so much time and spent most of it chilling indoors looking ugly. By the end of the holiday, my hair was nowhere near as greasy and I can now go 4 days or so without having to wash it. It does tend to revert back to grease pit if I overwash it again, though.
I would also suggest not using too much product. Use basic shampoo and conditioner. To be honest, you could try shampoos that strip oils, but I personally feel that this just backfires as it makes your scalp dry and then it tries to compensate by producing a **** ton of oil.
I use Mane and Tail shampoo/conditioner which is meant originally for horses but works well on human hair lol! Seems to have mixed reviews, but works for me....