Unfortunately there are not a lot of options available to you that may not adversely affect your credit in some fashion. A short sale will effect your credit and probably eliminate your ability to get the new loan for your new home. In addition you could potentially be responsible for the balance of debt on your home that the short sale did not cover or be responsible for payment of taxes on the amount of the loan that was forgiven. If you can qualify for the loan on your new house without selling the old one then renting it out may be your best option. You would have to talk that over with your lender.
I would be happy to talk more with you about what your options may be. My office is in Newaygo and I deal a lot in the Howard City area. Give me a call or shoot me and email.... more