Hello, I Am A 23 Year Old Male, A Couple

Hello, I am a 23 year old male, a couple months ago a few blisters popped up on the shaft of my or is about a half an inch below the tip, once they popped they became sores which were slightly painful ad healed in about two weeks. I am uncircumcised and the blisters only pop up after unprotected sex with my parter, only if I don't clean my penis extremely well. This has happened 3-4 times now some worst than others. There is a very small out of discharge and hardly any Oder, I have good hygiene and I only have sex with one partner. I haven't gone to see a doctor which is my own fault. A little more afraid of the anther than anything else just hope it's nothing serious that I can get to stop soon!