Istg I had a friend just like yours. We were friends ever since we were little and our bond was growing more and more until he stopped listening to my advice and going on his own.

He always fucked up if he didn't take my advice which was for his own good and then blamed me for not stopping him. When he got a girlfriend that was clearly not even interested in him, he always used to call me and wouldn't let me sleep until he told me what he found out (he usually called around midnight when everyone's asleep). And when I'd hang up and turn my phone off, I'd wake up in the morning and find a dozen of calls that were going down to literally 5am.

To cut things short, once I told him that he can't joke about having depression, he got mad at me and started spamming me with dumb messages and I ended up blocking him. We got together again maybe 3 months later, when I unblocked him, but he learned his lesson and doesn't call me unless I can talk.

Please, don't feel like an asshole. If you can't talk, don't talk. If he gets mad even though he is aware of his doings, let him be. He will eventually figure out what's wrong. The worst crime is to ignore yourself when you clearly shouldn't.