Wow MamaBear, it's good to see you. I have to confess that I was starting to think you weren't ever going to come back. It's really great that you have done so well and you're right on track with a big weight loss! And didn't you say that at your very highest weight you weighed over 700 lb? If that is so then that's 200 lbs down already!
I am sorry to hear about your son. My son had some kind of nervous breakdown when he was 13 or 14 and he ended up in the emotional Care Facility. His teacher called the police and the ambulance because in front of the class he poked a safety pin through his eyebrow as if he were piercing it and just smiled at everybody. That scared me too but sending him to the mental hospital meant I had to give up care of him for a while and he was put in foster care after that. He ran away from every Foster facility and then ran away to god-knows-where for the next 6 months. So I wish you luck handling this and I hope you can have better luck than I did back then. However I must say he is now 40 years old and he is a wonderful person and everyone loves him and he doesn't have a shred of self-destructiveness in his body.
How is your support system? Do you have enough support to deal with this new wrinkle, of your son being self-destructive? I know that sometimes girls engage in cutting, but I have never heard of it in boys. It seems like he might have been cutting for a different reason. I'm sure you're already plenty worried about him but there probably isn't a whole lot you can do. He's acting out because there is something deep inside him that is controlling him right now. You didn't ask for advice, but I'm going to say just this one thing. Calmly listen to everything he says. React to nothing. Just stay calm, say I love you not WE love you, as in you're speaking for his stepdad. Let him know that you are there for him but very very calm about it because what he did was not a CALM Act. it was an act of frenzy.
I believe my son felt self-destructive at that time because his sense of Abandonment by his father had come to a head. It seems like it's right around the teen years that abandoned kids start to feel the worst. If I recall correctly your son's dad is not in the picture. No matter how much I loved my son, no matter how much I took care of him, no matter how much I sacrificed so he could have everything he needed, it could never make up for that hole in his life where his Dad was supposed to be.
My son idolized his father even though he hadn't seen him since he was 6 months old. When the father leaves, the kid makes him into a Mythic figure, and every time anything goes wrong with you, his caregiver, he thinks he would probably be better off if he had his dad there. In Alcoholics Anonymous they call that stinking thinking. And I'm not saying that my son got away without a scratch. He has permanent emotional scars and his father died a few years ago so now he can never meet him. It's a very tragic thing.
Anyway, welcome back. You were missed.