What Causes Penile Itching And Rotten Smell?

Hi Doctor,
Am Gautam from India.
I have question related to sex. My penial head has become more darker than before. At times, rotten smell is coming, itching is also too much.
I had safe sex with 4 diff partners so far. but had unsafe oral sex (received), took HIV test after 3 months from exposure (result came negative).
But still everyday that HIV, fear is killing me.

NExt, am smoking for almost 10 yrs.
i Feel pin point pain atleast once in a day in my left side chest ..
My left shoulder is also very painful these days..
A year back i took ecg, x-ray and the doctor said its gastric...but am afraid.

Pls save me from these two mental torture questions running in my mind.
Am not able to concentrate at my work.

Regards,
Gautam.