Welcome to HCM.
You are likely to be suffering from yeast infection of the foreskin and glans
of your penis and it is called as Balanoposthitis
It is more common when you are a diabetic. So get checked for high blood sugar and the presence of sugar in urine. If it so, it has to be kept under control. Otherwise it will recur quite often.
If your sex partner has yeast infection in their Vulva
and vagina, then also you may likely to get the same. If your sex partner on the family way or a diabetic she may have more chances of this infection.
If you meet your physician he/she will give the appropriate anti-fungal treatment for both for you and your sex partner. During the treatment sexual abstinence is a must.
You will be alright soon.