Poor impulse control, including lack of sexual inhibition, is quite common after brain injury. It speaks to damage in the frontal lobe, the area that controls our executive functions.
I would encourage you to go back to a psychologist. Don't be soured by your first experience. You do need to shop around to find one who understands your injuries. In the end, I opted for a forensic psychologist. She works with criminals - where TBI patients are grossly overrepresented - and really helped me, without drugs, with my emotional outbursts, etc...
Have you contacted the Brain Injury Association of American
www.biausa.org ? They can help you find qualified clinicians and offer support to your family. Your wife and son need help, too.
You sound like a very decent person. I hope your faith can guide you to seek the medical attention you need.