Pimple or pea size thing in penis end.

When put my finger from scrotum skin to inside deeper I feel a small size like acne type something I don't know what is this inside where my penis end inside the body where the pelvic bone is . After the penis end. I feel painful this position. This pain start after. hitting many times my penis side pillow which was very hard not like soft side pillow. This was happened on 2 nd April. After that day I feel pain right side scrotum area then I did USG of scrotum the report was good no testicle problem I take many antibiotics also. But still now today I feel right side scrotum . Now only 2 days ago 30 the June I scrotum area when I put my finger inside the scrotum i found a pea size or acne type something I don't know what to say it after my penis end portion where pelvic bone are there. in the last portion of penis skin inside body. I feel always pain for last 3 months after hitting my penis  on April. Before I had no pain . What is this pea size or acne type things happen and medicine