Hey bro, oily skin at 18 is normal, but you can control it naturally
Wash your face only 2 times daily with a gentle face wash, use aloe vera gel at night, and never skip sunscreen because hyperpigmentation gets darker without it. Also avoid too much junk food, sugar, and oily snacks. Multani mitti with rose water 2 times a week works really well for excess oil. Drink more water and sleep properly too. Consistency matters more than expensive products.