Why do people sometimes find it easier to talk to strangers on the internet rather than people who love and care about them?

My friend is in a bad place, I don't want to lose him but I woke at 4am to see he'd read my messages. I stayed up for an hour and a half hoping he'd reply anything just so I knew he was ok, but no. He talked to strangers on reddit instead. I'm not mad at him at all- I just want to help and I don't know how. Does anyone else find it easier just to talk to people they don't know?