What is the best way to retract a sworn statement?

I think you should probably take a copy of that statement to a lawyer, to look at this in some detail, and some of that "detail" might well be things you need to have kept in confidence.  Without knowing exactly what it is that you swore to, how true or untrue that might be, and what's at stake in the lawsuit, it's very hard to give you a read on this.

You are obviously at risk for false swearing.  If the case goes to trial, you may well be called as a witness and if subpoenaed, you'll have to appear and testify.  The damage you've already done might prove difficult to undo.