What are the repercussions if I walk away from my home?

My husband and I bought my current home in 2001. We refinanced it 3 times and he also took out an interest only equity loan. Both loans belong to Bank of America and both are in my husband's name, only. My husband passed away a little more than 2 1/2 years ago. I am executrix of his estate (which consists solely of the house) and had the title transferred to my name. I have been paying on both loans. They are up to date and have never been in default. The problem arises because I am under water on the house. According to Zillow, it is worth about $47,000. With both the mortgage and the equity loan, $131,000 is owed. I can buy a better house for less. I have excellent credit (which I don't use)and a pension, so there is no problem with buying another house. B of A will not discuss loan modification or refinance unless I assume the loans. What legal repercussions are there if I walk away (after buying another)?