I have serious pain in my abdomen and below. i went to the doctor and all they could say was it was a sex related injury and im swollen is this normal?

Maybe: It would be appropriate to check some blood work, urine tests, pregnancy test, and also consider a pelvic ultrasound. The exam can give clues as to where the pain starts and if it travels anywhere. If the problem was sex-related, i would not have sex for one to two weeks to let everything heal appropriately.

Sounds serious !: I interpret a "sex related injury" per your physician to mean traumatic or infectious issue(s). Both, or either alone, can be very serious and progressive, unless treated quickly and aggressively. In such a context, the abdominal swelling you describe sounds even more concerning. Don't hesitate to seek another opinion asap.