What Causes Fluid Discharge And Pain In My Penis?

I had sex with this girl last thursday. I didn't fully get to finish my nut. Ever since my penis has been hurting and I have had like pre cum coming out of my penis all day long. It also hurts to pee and it hurts for my penis to get hard. The pre cum has got less everyday but my penis still hurts. I think I might have a kidney stone. I know she doesn't have an STD so I am not really thinking that is what it is. Could you please help me out and let me know what might be wrong with me.