Hello,
You seem to be suffering from 
thrush.
Thrush is a yeast infection (candida albicans) which tends to affect warm, moist areas of the body such as the vagina, penis, mouth and certain areas of skin.
Thrush is more common in people with 
diabetes as high sugar levels lead to better conditions for the yeast to grow.
Symptoms of thrush in men include the following although not all of them are present in one person....
Reddening or swelling or soreness of the 
glans (head) of the penis
Itching
Pain during urination
White curd-like appearance on the skin
Painful experience during sex
Treatment to be followed....
regular application of anti fungal ointment like 
CANESTAN or NYSTAN
Take some oral anti fungal like 
DIFLUCAN for few weeks.
Control your sugar levels meticulously.
Thanks