My Penis Is Very Sore All Around And The Tip

My penis is very sore all around and the tip look and feels as if it is infected. It stings when I urinate sometimes. I took a shower this morning and just the water made it sting very bad. Also, it has an odd odor. It has been itchy for a little over a week now but I thought it would just pass so I decided to wait it out. Now I'm a bit worried. The last time I had sex was well over a month ago. Please help.