it looks like mouth rot- maybe another member who has seen it in person can also look- are you sure he is only 6 mos? those are pretty big horns for 6 mos - I would get him to a vet- that looks pretty bad - will pray for you and your little guy
im on a crud phone and cant see well but it looks like one of two things. Mouth rot or a tempural gland infection. A vet is needed for both so go asap. You will need to review your houseing
Yes I would see a vet as soon as you can. When you see something that looks like that, and is that bad, I would just call the vet and see how soon you can get your cham in. Please let us know how he is doing.
Whether this infection started off as a temporal gland infection or some sort of injury to his gum is hard to tell from the pics. FYI, jax have a gland at the corner of their mouth that can get impacted and abscess. Herp abscesses don't drain on their own as the material isn't liquid...more like cheese. Just why jax are prone to this isn't all that clear, but it could be related to some sort of nutritional deficiency. Anyway, they probably get started when the cham's immune system is run down or overwhelmed by some other problem. The original infection can spread and they can be tough to eradicate. These infections can also spread to the sinuses if left untreated, so you do need a vet. Usually they will have to probe and clean out any abscess material AND give the cham some oral antibiotics to get at the bacteria lurking out of reach.
From your pics it looks like the infected area isn't right at the gland, but without seeing inside his mouth hard to be sure. These are painful and the cham may be reluctant to eat or drink just when it's so important.