It sounds like your /etc/fstab is using labels rather than the actual devices and the label doesn't correspond to the correct partition.
Boot in rescue mode, mount your / partition and edit /etc/fstab to use partitions rather than labels and it will probably boot then.
Redhat 8.0 Rescue mode
# Redhat links
RedHat Linux Manuals
Maximum RPM
rpmfind
Easier software management:
apt4rpm -
Red Carpet
RedHat 8.0 Tips & Tricks
# Redhat 7.3 down configuration commands
setup leads to several configuration tools
# Redhat 7.3 up configuration commands
Configure soundcard:
redhat-config-soundcard
Configure X server:
redhat-config-xfree86
Configure network:
redhat-config-network