Rule #1 is not tweak anything in the system perl core libs as they are used by your OS.
before your upgrade u could have backed up /usr/local and .vimrc and any pertinent files/libs to an external drive..
Someone recommended perlbrew with cpanm to me the other day and there was no looking back for me.
a simple command like perlbrew switch perl_version ensured i am looking at the currect library paths for the current version of perl i want to use.