Should I walk away from my mortgage?

No one here can give you advice on this without knowing your personal situation. But if your mortgage is "upside down" one can make an argument that if you can find an equivalent property for rent at a lower monthly lease than your currently paying in mortgage, taxes, and property insurance it can make financial sense to walk away. You have to balance the financial gain of doing this against the hit on your credit score that you'll take, and basically resolve to rent (not buy) for the foreseeable future.