My son is suffering from depression again

Sorry I haven't updated in a while. Anyone who's been through this rollercoaster with my and my son know everything. He's biological my step son and he has had a lot of issues in the past. He was drinking, on drugs. Suicidal, stealing, not bring respectful. He dealt with sexual abuse. He was at one point when he was 10 raped to the point of being hospitalized. His mom is trash and takes no responsibility for allowing it to happen and signed her rights away and talked about his sexual abuse on Facebook. He's come a long way. He did have a relapse but is sober again. He loves his baby brother. Favorite movie is brother bear and watches it with his baby brother all the time. Me and him are super close now. He even told me he lost his virginity. Through me off but he was happy because it was the first time sex was consensual. And he is 17. He has been extremely depressed. Like laying in bed all day. He won't even get up to go to therapy so I'm gonna see if his therapist will come here. Idk what happened. I think him and his friend had a falling out. He made a friend at his new school. He spent the night that weekend and came home at 3am and went straight to his room and stayed there. He won't eat or talk. Just stays huddled in his bed.... My husband can't get him to talk. It seems he's fallen into severe depression.