Suggest Treatment For Burning Sensation After Urination

I have a problem; I have a mild stinging sensation after I urinate. It just started 2 days ago. I also have to pee more frequently (possibly because I have been consuming more liquids). It all started after I drank some 180 proof liquor with no none alcoholic chaser, I also masturbated. After that I felt pain in my lower back I also felt pain in the tip of my penis AFTER I urinated. There is no abnormal discharge, nor does it hurt to pee. I also feel it when I sit for an extended period of time. It feels like it is the bottom part of the opening of the penis head. It is more like a slight pinching. I do not have any swelling. It lasts for maybe 30mins or so after urinating. But I have to urinate frequently. I did have non monogamous unprotected oral sex with a female about a month ago. I hope it isn’t a std. my eyes are not yellow. My feet do not have any sores. My anus does not itch. My testicles do not pain. it is just my lower back and my penis. Please help