Naltrexone is an opioid antagonist that is approved for the treatment of both opioid dependence and alcohol dependence.
It would not help with your cat addiction.
You need counseling, substance support groups, staying away from the people, places and things associated with your use.
I haven't,but hang in there. I know I've seen others use it on here. Hopefully someone can come On soon and tell you if it's helpful or hurtful.