Note that I am not licensed to practice in your state.
If the bank forecloses on one home, the other home is not at risk. The bank only has collateral on the home they lend to and foreclose on. You might still owe the bank the difference between what they can get at foreclosure and the outstanding balance of your mortgage.
Unless both homes are collateral for the mortgage being foreclosed on, the other non-foreclosed home is not at risk with the following exception. Should you owe a deficiency to the lender after the foreclosure, the lender becomes a creditor and your house would be an asset to go after. Perhaps you could negotiate a deed in lieu, or short sale to protect your new home. I suggest you consult with an attorney in your area to discuss your options.
In Illinois your home is available for a homestead exemption - 735 ILCS 5/12-901. That amount is $15,000 of equity in a home ($30,000 if you are married and you both claim the exemption). You alos have other exemptions such as an exemption in miscellaneous household property $4,000 and exemptions in vehicles $2,400. (All of which are doubled if you are married).
The bank could get a deficiency judgement against you if the second home does not sell for what is owed on it. That is a judgement against you which they can collect -- by levying against your other assets (if they are not exempt) or by attempting to garnish your wages.
The short answer is that no you should not be in danger of losing the home you are living in -- the real danger is that this may be a snowball rolling down the side of a mountain. The creditor might agree to a short sale -- a sale for less than what is owed on the home, in which case they won't be able to seek a deficiency judgement against you. Unfortunately the creditor has to agree to a short sale -- a judge or you cannot force them to accept a short sale.