I created an alt account just so I could write to you.
Your BF is revolting, and 2 years ago I was in your shoes exactly.
When I first met my BF I was attracted to him enough that I could see past his hygiene. I fell in love with him during that time. Eventually the crazy new love hormones wore away and it became clear to me that my BF did not know how to use soap and deodorant.
At first I noticed he didn't have soap in his shower, he played it off as if he had just run out. I noticed he just liked to stand in the shower as the water ran over his shoulders without actually washing anything. This was a lifelong habbit. He emerged from the shower with just as much BO as when he went in.
I started gently reminding him when we were in the shower. When that didn't work I would soap his body for him, hoping he would get the hint. This only worked when we showered together. Being nice didn't solve anything. Months passed and I got emotionally exhausted.
I began being direct. It improved a bit, but the habit was hard to break. He simply didn't know how thoroughly he had to use soap, and that deodorant prevents BO, and doesn't mask it.
I started thinking about asking r/relationships what should I do? I love this man and didn't want to lose something amazing. Why couldn't he just take 2 minutes a day to prevent his bad smell?
After six months of gentle reminders and direct 'remember to wash under your arms!' I started thinking about breaking it off. Having sex with his was gross when his BO filled my nose. Hugging made me turn away. I was so angry and frustrated.
I think you are at this stage.
My next step was to sit him down and tell him it was over unless he washed effectively with soap and used deodorant as he was still clean from this point onwards. And I meant it. I felt like a bitch, but my disgust and self respect was more important.
You need to do this. Tell him that from this point onwards, unless he washes his stinky smegma you can't be with him because it is repulsive. Then stick to it. Confront him. It will take you ten minutes. Do it the very next time you see him.
If in 2 weeks he still has revolting crotch stink you dump him. You're too young for this shit.