There's nothing you can do to treat him yourself, unfortunately. Your Jackson's chameleon has a very severe temporal gland infection (TGI) which can be seen in the corner of the lip. When left untreated, the infection can spread, causing the eye to bulge and bloat. He needs vet care asap. I know the vet can be expensive sometimes, but he will only get worse. These infections do not resolve over time.
TGI can occur when Jackson's aren't getting the cool temperatures they need. Over time, warmer temperatures can cause their bodies stress which can weaken their immune system and leave them susceptible to infection.