I have a business commercial loan and signed personal guarantee is my home at risk if I default? -

Absolutely, your home is at risk. Personal guarantee is putting up your personal assets for collection should you default on the loan. Your only and I mean only hope at this point is to get a good lawyer. They can advise you on if the contract will stand up in court. Some will, some will not. Lawyer up, ASAP. You can not meet with a professional too soon in this matter.

i would advice u not to default,every loan carries its own consequences and banks would not hesitate to go according to the paper you signed before the loan,good luck!