How do I remove myself from a credit card when I’m not authorized to do anything to the account

Location: Minnesota

So about a month or two ago my step-father took out a credit card in my name (could be more for all I know now) with him as the authorized account holder. Now, he didnt ask, he simply told me about it after it had already been done and just said “it’ll help build your credit.” 2 weeks ago we had a big falling out for reasons that aren’t important. I just went to see if I could remove my name from the card and learned that not only does the credit card I know about have over a $900 balance on it (I’ve only used it once at a walgreens for like 5-7 bucks), but since I’m not an authorized account holder, I can’t even dispute the claims or even remove my name from the card or account. I can’t do anything and he now holds my life in his hands. He also froze the card, if that’s relevant. What should I do in this situation? Seems to be all I can do is just call the cops or take him to court but I don’t even know how that would pan out. All help is appreciated.

Edit: Removed flair.