@feruze-- Are you using sun protection cream? You need to use face creams and body lotions with sun protection (minimum SPF 30) year around. When you go to the beach, don't go outside between 11am and 3pm. This is when the sun's rays are most powerful and don't sit in the sun. It's possible to tan in the shade as well. If you go in the water, you need to re-apply sun protection cream afterward.
Also, I suggest using aloe vera gel and vitamin C cream as dry skin remedies. Aloe vera is very hydrating and healing for dry, sun-burned skin. Vitamin C helps fade dark spots and will help with your hyper-pigmentation.