KEY thing to pay attention to right NOW: He has SUICIDAL thoughts.
Do not get sidetracked by other things now by natural remedies etc..... as it may just delay what needs to be done NOW. Which are his suicidal thoughts... which can occur, at anytime and get acted out on at any time.
Do not leave him unattended... check on him, especially when he thinks he is "alone."
Then in tandem with that, sure, you can research other PROFESSIONAL treatment. But again, NOW you must take his suicidal thoughts seriously.
Depression is expressed in many ways... bodily pain, stomach aches, headaches, insomnia, etc. But the OVERALL thing, is to address the OVERALL problem... his suicidal thoughts, and linked depression.
Keep communication open with him, keep tabs on his thoughts... suicidally. And act on it, now.
If need be, perhaps let him stay home for now... he is unwell. And then maybe he wont' get so tormented by going to HS now, when he cannot take care of himself. He cannot take care of himself. He CANNOT take care of himself and his mental/emotional well being. Take heed.
Your son's problem is MORE than just peer pressure or social problems. He has Depression. Take him to a professional....
and remember... he is SUICIDAL. AND, giving a Suicidal person sleeping-pills is NOT something you should do.
Sleeping pills, is NOT GOING TO CURE him or his Depression NOR his Suicidal thoughts. Sleeping Pills has killed many depressed people. Remember Heath Ledger, the actor? That is just one example.
Taking him to the Doctor to see if something is wrong with his stomach... is, not going to cure his Depression. Which is THE problem. You NEED TO TELL THE DOCTOR about his DEPRESSION... AND SUICIDAL THOUGHTS. Have you done that? Does the Doctor know? You NEED to tell the Doctor.
Take him to the ER or Hospital... and seek a Therapist right away. Ask the Pediatrician for a referral and recommendation.
Just CONTINUE to be there for him no matter what & so he does NOT feel 'alone'... and keep tabs on him.... just in case he tries to attempt suicide. There is only so much guiding you can do... since he has a serious mental health condition, and beyond that, A professional therapist must be prescribed.
He is reaching out & crying out for HELP... and desperately. Which is good, he told you, instead of hiding it from you, which would be detrimental for him.
All the best,
Susan