Hi J.,
I would for sure contact an attorney. I know they are expensive, but you could be very close to having your own wages garnished, or from having a lien put on some property, or being brought to court. Sometimes, all a collection agency needs to back down a little is to receive a letter from an attorney. ;-) Most attorneys will do a free consultation.
I don't know about WI, but in MN, you can tell a collection agency in writing that you don't want them to call you any more. They can still send you stuff in the mail, but they HAVE to stop calling you. In MN, the Attorney General's office handles collection agency complaints. I would suggest calling the WI Attorney General's office to see what your "rights" are. Collection agencies typically can not call you repeatedly, be harassing, or call outside of "normal" hours.
I would also, starting immediately, stop talking to any and all collection agencies, and whatever you do, do not pay these people with your own money. Once they get a dime from you, they will chase you to the ends of the earth. If anyone should be talking to them it is your husband. My parents (who live in WI) were the co-signers on someone's loan, and now that person is failing to pay their loans. My parents are now getting calls. Their lawyer advised them to NOT pay anything and to NOT talk to the lenders.
If there is no chance of your family paying these loans off, you should consider one form of bankruptcy or another. There are certain kinds where you "reorganize" your debts and pay back a portion, and there are others where all your debts are simply discharged and you start with a clean slate. Depending upon how your husband's business is set up, the business itself *might* be able to file bankruptcy.
I know someone in WI who filed what was called "injured spouse" to protect her own wages from being garnished for child support that her husband owed. I don't know if this can be done for other types of debts.
You, or really, your husband, need to contact an attorney anyway. What your husband did (saying he was single when he was not) might be loan fraud, and you could have a serious legal mess on your hands. Good luck to you.