Walk away - house and mortgage

Hello everyone… I need opinions! I bought a house 3 years ago. Though the property deed is in my name, the mortgage is in my Grandmother's name. This is because I had bad credit at that time. I have made all the payments to it since then. But as I am going through financial crisis, I can’t make the needed repairs.. Now I am planning to move out. How will this strategy affect my credit? As per my knowledge, my Grandmother, is the only one whose credit would be affected, I assume. But she is dead now! Since I am only on the deed, seems to me that the only consequences would be with the county and property taxes but those should be paid through the next year. Thoughts?