One of my best friends in high school got hurt playing rugby with a few friends. He just slightly hit his head off another kids head, but he shook it off and just went on with his day.

Later that afternoon, he collapsed during a family dinner and died. He had a brain hemorrhage. He would be alive today if he had just not been stubborn and went to the ER like we had suggested.

Your situation sounds nothing like his, but like others have said: see a doctor ASAP.