Will he be back? Advice needed

It’s been 3 weeks since he ended things with me after a happy 4 year relationship. He was cold and didn’t show any emotion at all. It ended very quickly and kind of out of the blue? He ended it via text message after saying he just needed some “space”. But continued to tell me during our “space” that everything is fine and that he still loved me etc. I’m beginning to think maybe did he check out a long time ago but just stuck with the motions of the relationship and then just ended it when he couldn’t pretend anymore. We stayed in contact for the first 2 weeks. I was reaching out to him. He wouldn’t always respond. We still had each other on all socials. He would be one of the first people to view any of my stories. He wouldn’t respond to all of my messages but some he would. His numbers went up on social media, friends etc. And then he blocked me a week ago and I’ve not heard from him since. I’m broken. Truly and utterly broken. I’m beginning to think is he a dismissive avoidant? I’m new to that phrase but he seems to have all of the traits. I want to know if he’ll come back? Will he ever regret his decision? Will he hurt like how I have been hurting the last 3 weeks? Has anyone had any similar experiences?