Is it possible to reverse the sun damage on my face?

Depends. Sun damage occurs from excess time in the sun and the sensitivity of the skin to the sun. It can be improved upon but not fully reversed. The earlier you start the better. Mild sun damage can use good skin care products, regular peels and intense pulse light lasers. More severe sun damage will need good skin care, deep peels or resurfacing lasers to help. Use sunblock, minimize sun & no smoking.
Improve it. You can prevent further damage with sun protective blocks and improve the quality with a regimen of skin care products, facials, hydration and limiting sun exposure.