Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern..
As per your complain there is a possibility that you have got an 
Allergic reaction to the components of sunban cream leading to dryness and red patches or rashes over the face..
I would suggest you to completely stop using the sunban cream..
Wash your face frequently throughout the day with cold water..
You can take anti allergics like Levocetrizine..
Do cool compresses over the face..
Gradually the redness will start subsiding and skin will improve..
Once the symptoms improve then to relieve the dark spots you can start washing your face with 
Salicylic acid and 
glycolic acid containing facewash..
You can apply creams containing 
Kojic acid, glycolic acid and arbutin.
Apply Vitamin E containing creams at night..
Exfoliate your skin twice a week using a gentle scrub..
Limit sun exposure..
You can also take Vitamin C supplements..
You can also go for treatments like 
Microdermabrasion and chemical peeling..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora..