My cactus is sick? ;; Brown spots and scars!

Hello Everyone!
I would like to adress my thanks to this forum, since it helped me to take care of my barrel cactus and my prickly pear :3

So here I go,
my cousin gave me two pads of her cactus, one that is as long as their house's wall. It's some triangular kind, I don't know it's name.
Sadly, on our way back to our city, the longer pad got reaaally dried out, lost it's colors and started bending really hard.
I was hesitating wether or not cut it, I really don't want to, to be honest.
And now it has brown spots, maybe sunburn? And so much scratches over it, and a bit of it looks like it has been eaten by some bug.
The scartches are all over my prickly pear cactus too but I spot no discoloration, and it's growing beautiful little cacti.
This triangular cactus has a lil' baby too and it looks discolored like it. Maybe it's because it's still young?
Anyway, please help me decide! Should I cut? Or keep? ;-; It hurts me, thouuugh!




The huge bite of whatever bit it :

Hello,

There's nothing wrong with your cacti
The small new growth looks fine, it will become like the other part of the plant later. Just provide enough light for that
The brown part happens, plants gets older just like us and such things happens. If it is not rot, it's fine. On the photo it looks dry, so it's fine.
This cacti is a tropical one, and loves heat and water.

Yann (France, Clermont-Ferrand). Serre tenue hors-gel + pleine terre un peu abritée. -10°C tous les hivers.

Thank you very much :^) I'm relieved now.