I am so sorry to hear of your troubles as well. I hope you got legal representation for you son - the same thing happened to my cousin. She was having a difficult time, and made a passing remark "this is it" after her dog died, and she was involuntarily put in a mental institution. I called the public defender's office to help, but she was released after 3 days.
Maybe I can help you. All I do is research from the time I awake, until sleep, how to heal myself. Depression is linked to a damaged gut micro biome. If you have never studied it, it won't make sense to you. Certain probiotics have the ability to eradicate depression, as does vitamin D. Depression is often NOT a mental disorder - it is a physical disorder. And given the bad diets teens eat, it's no wonder. Let me know, and I can find out which ones to recommend you give your son. I planned a protocol for my friend's daughter, and for my daughter.
I too have alienated people! It was not due to being mean, I was trying to help and it was taken wrong. But yes, I feel the effects of my incomplete following of the Lord, and He's letting me feel it - or move in another direction. Which is how I wound up here. My daughter is looking for a godly man - God just hasn't allowed it to happen. I'm before His throne constantly. And you're right about the terms used with those brought into your family through marriage. I've tried so hard to be nice to her, but she only wants my son and her family. Unfortunately - he never calls or visits. Neither does my youngest. But a verse came to me: "...people hate the light because it reveals their evil deeds..." I speak the truth - and people don't want to hear the truth. So I can lie and stay in their good braces, or I can live the truth. Truth is important to me and that's what God requires.