Unfortunately, when the skin has begun changing colors and flaking off as you described, you have literally fried your skin to the point where all the underlying skin cells have died and are no longer useful to your body, therefore, it proceeds to get rid of it by shedding it off. You may already know that your skin sheds everyday on its own, but you speed it up to an unhealthy level when you get sunburn, and the dead, damaged skin MUST come off. So, no matter how much lotion you use, your body is shedding the damaged skin to make room for the new, healthy skin underneath, so stop wasting lotion and wait for your skin to heal properly.
P.S. More bad news! The tan will be gone once you're completely healed. Sorry! Don't cook yourself in the sun! There are hundreds of sunless tanners out there that work wonders, without the damage of UV rays!