Blunt Head Trauma

About 4 Months Ago I Managed To Trip And Hit My Head Into A Concrete Curb. Ever Since That Day, My Mental Faculties Have Gotten Poorer And Poorer. I Used To Be A A/B Student, Now Its Mostly D's And F's. My Logical Abilities Have Been Getting Worse, My Problem Solving Skills And Attention Span Are Shot To Hell, And I've Been Beginning To Have Thoughts Of Suicide And Indiscriminate Homicide. I Want A Straight Answer: Can Blunt Force Head Trauma Cause Any Kind Of Change In The Mental State?