Hi and welcome!
I am very sorry for your predicament. You sound like a very caring piggy mummy.
You can try to give Pete alone time for a short period (a few hours or a night that will not break the bond) and see whether he is perking up noticeably when away from Carl; in that case I would recommend to separate. If the two boys still want to be together, they will tell also you.
Make any further decision from whether your boys still have a viable bond. Please be aware that even a temporary separation will require ideally a buddy bath (considering Carl's hormonal overload), an introduction on neutral ground, a thorough cage clean and lots of dominance behaviour when they get together again. Have an oven glove at the ready to separate; do NOT use your bare hands to get in between your boys!
Once you separate for good, it is most likely that your boys will never get back together again and you may have to look at alternative solutions.
@Tbag has given you all the information threads with the tips. We can talk you through any further options once you know how things lie between your two boys. I am very sorry for you; it is not all that often that things go wrong at this late stage, but when they do, it is usually pretty serious. It is alwaya a very gutting realisation for any loving piggy mummy.
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