although he doesn’t deserve me he said he wanted to let me know
Run 1000 miles from anyone who starts with the "I don't deserve you" crap. It's emotionally manipulative. They do think they deserve you, in fact they think that they are better than you. It's a line and it's used deliberately to invoke sympathy and to get a whole load of "Of course you do, you're a great person" type comments.
No, no, no. I was badly burned by falling for this line that's why I'm so militant about it
Anyway, there's no excuse for blocking you like that. If he was having difficulties he could easily have sent a short message about it to let you know.
Maybe he did have problems with his ex-wife and maybe you could believe his story but this incident has shown you how he deals with any issue which comes up. He withdraws into himself, leaves others in the lurch/hanging on with no explanation, he "spirals downwards" (also evocative, manipulative language like the I don't deserve you thing, and then once the issue has been resolved he then reappears expecting to take up where he left off.
This is how he will react in any situations in the future and if you were to progress to a relationship with him, that's what your life would look like. Anything happens between you or there's an emergency with a child or job loss or whatever, he'll be off into his spiral of despair and leaving you to deal with the whole thing.
I'm not sure I believe you though. More likely he was dating someone else at the same time, thought things were progressing well with her, turned out they weren't that great or she dumped him and he decides to unblock previous online dating contacts to start up again with them..
You do not need this in your life.