need info please

My son (18) has yelled and threatened to hit me, and I told him if he ever did I would have him arrested. He did last Oct. It wasn't a really hard punch, and it was only one, but it was to my chin, so I did have him arrested and left him there for a couple of days. His court date is coming up and I need to know if we need a lawyer and exactly what the paramiters are that he could recieve. (we live in Texas). I really did it to teach him a lesson not to have him sent away for a while. I am hoping that he might get community service or probabtion instead of jailtime, and was wondering if that was a possibility. He does not have a record, never even a speeding ticket. He is currently a senior in High School and has been accepted on Academic scholarship to UTT. He has been seeing a psychiatrist and he changed his medicine to a different drug. He has written a letter stating that his anger seems to be under control with the new drugs and counseling. Does he have a chance of it going easy on him and getting to graduate in May and go to college in August. I cannot afford a lawyer and was wondering if he really needs one.
The charge was assualt/family violence, I hear that makes it worse. Is there a way to get it reduced?
Thank you for your help,
Vikki

You can testify that you really wanted medical and other help, and he has received it.