in reply to cpan suddenly fails
From @INC, it looks like you are dealing with the system installation of perl, which was probably installed as a package as part of your system. With some parts installed from packages and others installed from CPAN, it is possible to make your installation dysfunctional.
You could try re-installing system packages to bring things back to a consistent state, after which you might abstain from installing to the system perl from cpan until you have learned enough to deal with the problems that sometimes occur. If you can, install everything you need from your system's distribution packages.
If you need modules from CPAN that are not available from your system distribution, you might do best to put a separate installation of perl on your server, to avoid conflicts with the system installation. You could install a more current version of perl, which would also help you avoid problems with new CPAN releases that don't work well on such an old version of perl.
Installing perl from source is not very difficult, but can be overwhelming if your system does not yet have prerequisites (compiler, make, libraries, etc.), particularly if this is unfamiliar to you. If you are interested in such things, it might be a good learning experience for you. Otherwise, you might be able to get someone familiar with installing perl to help you.
If this is a production server ("on-line" suggests it is), you would do well to practice installing on a less critical system, until you are confident you know how to do it successfully.