Boy advice

So me and my now ex have been together for about a year and a half, we broke up about 2 months ago over lifestyle differences and made our way back to hanging out all of the time because we missed each other. So things have been going good, it's weird bc we are still acting like a couple but there's no label. We have all these summer plans for August and all of the sudden today he says it's not working anymore. Out of literally nowhere. I'm so heartbroken and he won't answer any of my texts or calls. It just doesn't make any sense. And we work together so I will see him on Saturday, what should I do? Should I block him? And what do I do when I see him at work?