My personal opinion is that you should go to the police and file charges. Don't mess around with him. Throw him in jail as soon as you can get it done. No threats, no warnings, just BAM! here's your summons.

From a husband's perspective, I would like to think that my wife knows that I've got her back. That if someone threatened her with something like this, the backlash against him would be immediate and severe and would have no affect on our relationship. Stalling, not going to the police and such would personally throw doubt into my mind and would probably make me consider the worst.

So that's possibly something else to consider. That your fears of people finding out might actually cause more problems instead of them knowing and being able to support you.