Its hard to know exactly how he must be feeling or what he may be going through, but I think reaching out was the right thing to do. It may not feel like it, but when I am in a low place knowing someone is there and cares can help. That being said however I think you should give him the space he asked for. You let him that you are still there for him and maybe that is all he needs right now. Maybe you could trying checking in with him in a few days? I hope this helps and if you need someone to talk to, I'd be more than happy to.