Eat less oily foods. The oil comes from whatever you're eating.
As somoene who had severe cystic acne as a teen I tried everything including prescriptions they later recalled and had class action lawsuits for.
And I'm still plagued by occasional breakouts at 44. If you have oily skin you have to suck it up and get used to it, and watch what you eat. Could be worse though. If oily skin is the worst thing you have consider yourself blessed.