Suggest Remedy For Penis Problem

I am 30 years old male and lately I am experiencing lot of itching on my penis tip. It happened day before yesterday for the first time, I dint cared much and itched a lot but from yesterday I am getting lot of white/yellow substance on penis tip and the skin on tip has swelled. I dont think it could be STD since I had sex 4 months back that too with my wife.

Please advice I am really worried, would really appreciate if you can advice some medicine or some home remedy. Thanks