Hi, thanks for posting your query It seems you had a severe sunburn reaction which is characterized by pain, swelling, dizziness, nausea and fever in addition to redness and burning . To treat the same Do cold compresses over the burnt area and frequent cold water baths Apply cold Aloe vera gel You may apply hydrocortisone cream continue ibuprofen Avoid further sun exposure till it heals. Drink plenty of water Take oral beta carotene and antioxidants Though you used a sunscreen but you need to use it as follows: Apply sunscreen about 30 minutes before you go outside. Repeat every 3 -4 hours. Apply liberal amount that is about 1 ounce each time . It should cover both UVA and UVB rays. If the symptoms worsen you should immediately contact your dermatologist Hope this helps you wish you a speedy recovery