Suggest Treatment For Lump On Tip Of The Penis

I noticed a lump on the tip of my uncircumcised penis, by the urinary tract. It started off red, then turned white at the tip of the sore, and now is a blackish purple colour almost like dry blood. I have been following up with it for 2 months. What could it be? There is also a nasty smell coming out of penis also. I am 28 and weigh 195, 5'11" and healthy, help me out please!