The wounds are from his backs legs grabbing his front legs in the same exact spot every time. He just keeps trying to get out of his own death grip and his nails are so sharp that they sink into his skin. He never ends up letting himself go. The wounds are really bad because he does this so much every day, near the same spot each time, making the wound bigger and fresher. I have to check on him every 15-20 minutes or so to make sure he is not attached to himself, or else he will just be stuck on the yoga mat all day until I or my boyfriend come to his enclosure to untangle him. When we do untangle his legs, we really make sure to kind of wean his nails out of his skin, instead of just yanking his legs off, which would obviously make him bleed more

I will definitely up the mistings for sure, and lower the temps. It's just every time I lower his temps, he always turns dark as if he is cold, until I up his temps back to where they are now. The vet told me to up his temps to make sure if he had any respiratory issues, it would help fix that problem? I believe that is what she had told me. And, as you said it may be the case, the skin around the wound IS actually necrotic. It is dried up and dead, that is why it looks somewhat blackish/brownish around the fresh wound. Will the hydrogen peroxide sting him? He's been through SO much and I just feel awful for him. I feel like he associates me with everything bad happening to him since it's been all within a couple of months. And if I do apply that polysporin, would I leave it as is or should I try my best to cover it up with the homemade bandage I tried to make for him?
Yikes, that is quite the tale of woe--so many vet visits and no resolution....
Am I correct that there are three issues: No appetite, sores that will not heal plus mobility issues?
Your first picture shows all kinds of swellings down the front leg. I wonder if he doesn't have a systemic infection. Why hasn't your vet prescribed an antibiotic? My reptile vets have always gone to a broad spectrum antibiotic when they are stumped by ill health when all other avenues have been explored.
His nails won't damage healthy skin. I can bend the needle on a syringe trying to give an injection--their skin is that tough. When I do a necropsy, it is actually quite difficult for me to start a tiny incision into the skin using really sharp pointy dissection scissors. If his nails are damaging skin, there is something wrong with the skin.
I would really like to see a picture of your cage. Normal chameleons will grab their front legs with their hind feet if they are out in the open. Please send a picture of his cage set up.
I'm not sure about your temps--I'm not a veiled expert--but you want his temps on the high side of normal since he is ill. It seems you are running an automatic mister for too long--60% to 70% of the time is a heck of a lot of water. My chameleons won't eat when my mister is running. I have a species that comes from an area of 400" of rain a year and I only run the misters a total of maybe 10 minutes during this time of year. I ramp it up as the weather gets hotter and the air dryer, but right now, only 10 minutes a day give or take a few. That is nowhere near your 60% of the time. I can't imagine dealing with all that waste water.
His inappetence could be from many reasons, including a systemic infection.
Weekly vet visits for two months suggest your vet doesn't have a good handle on what is wrong and another opinion is in order.
By the way, I have a sickly chameleon that my vet and I call "He Who Would Not Die." HWWND has suffered from ill health since import in December 2014. I adore him. I've spent a fortune on him. We don't know what is wrong, but suspect his biggest issue is that he has abscesses internally. He's been near death many times, in fact a year ago I set up an appointment to euthanize him (something was intermittently blocking his airway and he was collapsing from lack of oxygen) and do a necropsy at the same time. (Both my vet and I are really interested to see what the heck is going on with him internally when he finally does die.) We decided to try one last ditch effort even though the vet did not believe there was a bacterial disease process going on and surprise surprise, he survived and earned his nickname, "He Who Would Not Die." And then he thrived. Thrived to the point I introduced him to a female earlier this year that I hope he bred. Of course, the stress of a breeding situation caused a downturn... He was a the vet's again last week and is on another series of antibiotics. I won't know what is wrong with him until he dies or I euthanize him, and even then I might not know without hundreds of dollars for pathology.
You might never know what is wrong with your chameleon as well. I wish you luck and hope you get him right.