Next time when you seek help please provide your state information. You could be in Canada and put us in danger of unauthorized practice of law.
Here is some general information not amounting to legal advice:
One instance of such abusive behavior will not be enough as significant change in circumstances to support custody modification.
For the rest of your questions such as your might-be strategy, you should consult an attorney from your local area because those are legal questions that must be answered by an attorney.