It sounds awful because it is awful. If a woman has sex with a man with an abnormally large penis, or sex is way too rough, the penis can touch and bruise the cervix. Women will often feel abdominal pain, and even notice some bleeding if this occurs.
What to do
There isn’t much one can do to speed up the healing other than refrain from having sex for a little bit. You can also see a doctor about getting medications to deal with the pain.