I explain treatment and precautions point wise manner
1. Avoid direct sun light exposure as much as you can. Wear sun glass , caps and cover exposed part of body all the time
2. Use sunscreen thrice in a day lik 10 oclock, 12 and 3 oclock all over face
3. Sunscreen SPF should be around 50.
4.Use anti pigmentation cream over pigmented part like
kojic acid, hydroquinon, depiwhite cream etc.
5. If
tanning is deep and too much then ideal treatment is
glycolic acid peels. Sittings of 6-8 peels must be required.
6.Never stop sunscreen even if tanning go off.
7. Rule out
thyroid ,
diabetes and obesity. All three factors help in tanning lot.
as you said you have tried al the cream so best is chemical peeling 30-50%. it will take 6-8 sitting with gap of 1 moth.