Penis problem. It. what test i could!

Sir I have a problem which I face from last 6 months. I am treated by 2 doctor but I am not healing my problem. Actually I have a wierd sensation in my penis the opening head of penis inside I seems a white patches with feels like an ulcers. It's feeling burning all the time it's very irritated. And on the (glans)cone part of penis I seen some crank .. it changes colour I don't know it's changing or not but I think it's changing when it's having an erection this sensation is increased and I seems a red spot .. difficulty in urine sometimes it's come again and again sometime it's not. . Tell me what is the chances of getting this symptoms R u able to solve it .. What test I could regards this so i come to you with getting these reports tell me please