Most Helpful Guy
Based on what you've said here, he may go in and out of regret. Whether he does or not though, it's not something that you should hope for. He needs to get help for his issues or else having a long-lasting and stable relationship with him is not likely.
Most Helpful Girl
My ex has done exactly the same to me and I can completely understand how painful it is. It's guy's way of coping (he admitted that to me). Women deal with the pain immediately and move on, whilst men ignore it and deal with the pain much later on. That's usually when they start contacting you months later. He will most likely contact you after some time or at least unblock you.
It's been about a week since my ex boyfriend didn't want anything to do with me, didn't want us to be together, didn't want to talk to me, ignored me etc to apologising and finally opening up to me about how he's feeling and why he's been treating me like he has, today.
Give it time, focus on yourself and your happiness until then. Refrain from contacting him, he may eventually think about things and realise he let a good woman go because he couldn't pull himself together. Not talking to him will make him miss you more.