Can only talk about myself, so please take this and any other advice with a grain of salt. Every person is different and reacts differently to this.
The headspace he’s in right now is one of utter confusion and emptiness. For now the dread might be gone. But he is probably far from ok. What he needs right now is love. And I don’t mean hugs and kisses and shit.
Let me explain it this way: He needs normality in a cozy environment. Friends or family around him to have idk like a pizza together while playing games or watching something he’s interested in. The important part is that they are there in person and not everything revolves around him, but with him. If that makes sense?
He doesn’t need an intervention kind of “we love you” bs, which to me sounds like hell on earth. He needs to live the love. Cherish others while being cherished.
I hope my word salad helps. Sorry I woke up two hours too early and my brain is still trying its best booting up.
The reason our ancestors went on to live on land is because they knew what lived deep in the ocean. There is no sound reason to return there.