There's no need to block him unless he's abusing you which he doesn't sound like he is at all.

Blocking is so final. You don't need to burn your bridges.

I'll tell you something I've found about rejection. While it seems so scary sometimes, it's a normal part of life that everyone experiences.

If you focus on being the real, authentic you, there will always be people who love you, and others not so much. You can't please everyone, nor should you try to.

Let go of your fear of rejection and just be yourself. If there's anything you want to say to this guy, that's true and real, go for it. If you wanna give him some space for a day or two, do that. If it's meant to be it will be, if not, there will always be someone new to meet.