Traumatic Brain Injury
This can be mild, moderate or severe. It usually includes some time in hospital, lots of tests and often even some rehabilitation.
You may have been told that you have concussion. Isn't that something footballers and boxers get? What about the scary stuff in the concussion movie? That makes you worry about your memory and what it means for your future. All reasonable concerns.
In either case, Neuropsychological assessment can help really clarify what is going on - is there memory impairment (and if so what can you do to help it) or other types of problems. Information about what is the case for you, and what to expect can help you feel much better.