Hey Betty of Black
Just read all the posts. Wanted to throw out some thoughts to random things that stuck with me.
While calcium injections or oral calcium dosing was recommended, there is also no certainty that a lack of calcium getting into your animal was the problem, or that such treatments would have helped. This late in the game, it was probably the best advice though. Other explanations could have been vitamin deficiencies, organ failure, etc.
There was talk of using a liquid calcium product. It can be bought on-line too, and is not prescription required. It was mentioned that since it was syrupy, there might be concern about possible inhalation. For the record, while there is always a risk of inhalation with any oral liquid given to a restrained animal, it is only an elevated concern when the liquid is oil based, such as many vitamin A and E solutions in a non bi-polar solvent (such as what is in gel caps). Chameleons show a far greater revulsion to oil-based solutions, and oil is far more damaging when inhaled. Liquid calcium supplements are water based, and pose a far reduced risk hazard. I have dosed thousands of chameleons with liquid calcium products and never lost one. I learned the hard way with oil-based products, and I did not need to dose even 100 to find out.
Since your animal had laid eggs recently, this could have antagonized an existing calcium issue. It is not uncommon for egg production and egg laying to push calcium-weak females over the edge.
I agree with those who say that freezing may cause some distress to the animal, along with decapitation. I also feel it is equally or more ethically challenging to let an animal die a slow death if no other means of euthenasia is available. I therefore applaud your decision to freeze the animal given the ready (or not-ready) options available to you.
A friend often says that "those that know the most about chameleon keeping have also killed the most". There is a direct correlation. We learn. Good luck in the future.