I’m sure you could have fixed it with GRUB Rescue. It’s slightly annoying, but it isn’t that hard to get booted from that. Once you get it to boot then you can fix things.
Don’t give up so quickly next time. It’s useful to learn how to fix it instead of just accepting failure and resetting everything.
I have my system select the default option really quickly, so I don’t see GRUB. This makes it tempting to not do that, but I think I’ll accept the convenient option instead of the cool option still.