I don’t think you were following strict sunscreen application techniques. I will explain below. Sunscreen should be applied every three hourly. Not matter what the SPF the sunscreen claims, they all melt away from the skin within 3 hours of use that’s why one time application will not do for sun protection.
Please follow instructions on how to use
Also I advice you to take Glutathione 1000mg once daily
Next Steps
Apply sunscreen in the day time every 3 hourly eg 9am-12pm-3pm apply all over the face neck and arms and leave on for 20 minutes to dry and then go outside