It is really difficult to deal with oily hair. We have a harder time in this regard, especially in winter. To save your hair from getting greasy, you should first wash your hair with water that you have waited for a bit, not with the water flowing from the tap. You should reduce the oils and shampoos that you apply to your hair.
Touching your hair frequently makes the follicles in the hair active. Hair stylers make your hair get oiled faster. Try to use these tools as little as possible. SLS-free shampoos will foam less but clean hair very well. Try to use these shampoos. One of the reasons why your hair gets oily may be that you change your pillowcase less than once a week.