You are better off re-installing.
EOS encrpyts your kernel and initramfs. This means that grub has to unlock the volume before loading your kernel. Unfortunately, grub does not provide a lot of options at that point
When distros, like pop, are showing you are a “pretty” unlock screen, they are using plymouth or something similar to do that. However, that requires that your kernel and initram be kept in an unencrypted location. If you are OK with that, during the install create an unencrypted /boot partition. Then you can install plymouth after the fact.