Retinol is a potent ingredient. If you are new to retinol, then you must use it 1-2x a week and make sure to incorporate hydrating and moisturising properties. After the skin getting used to it, then gradually increase the frequency in a week.
Do you use the retinol everyday? Do you add hydrating or moisturising ingredients into your routine when using the retinol? If you're using it everyday, try to stop the usage and lower the frequency in a week. Try to add hydrating and moisturising products as well.
Also, make sure your routine doesn't contain any exfoliating agents as retinol aren't meant to be combined with exfoliants, or other potent ingredients like benzoyl peroxide, etc.