Hi ML31,
I've taught High School for over 10 years, and mostly 9th graders. I have seen many, many teenagers over my career. High school is a real adjustment. Ninth grade and age 14 is a difficult age for both teens and their parents. Having said that, I strongly suggest you make an appt. with your regular physician for your son and make sure your doctor knows why you are concerned. The doctor should also talk to you. I think it's best if the 3 of you chat for at least a few moments to let your son know you are a support for him. Additionally, you need to know what's going on. Do not be shy about getting a second opinion. Rereading your note - a student who doesn't get along with anyone, and I imagine he sleeps or puts his head down during many classes, and doesn't complete homework is certainly at a risk for not earning his credits to graduate. I know you can imagine how that would make things worse and worse.
Keep track of his grades and classroom behavior by contacting his teacher. Ask your son's Guidance counselor to speak to him, perhaps on an intermittent, but regular, basis.
I commend you for noticing the change in your son's behavior and mood and, then, seeking help. You must be a good Mom. Lois