Death/Equipment loss caused by lag from Wither battle

Finally able to summon the Wither and the game lagged violently, causing my death and loss of all equipment without any chance of recovery. Now I cannot enter that portion of my world without extreme issue. I was very much looking forward to this battle and feel cheated. Is there anything that can be done to re-do/undo this situation so that i can have my battle properly?

If it matters at all; I am still a bit of a noob so this loss is extraordinary for me. Hours upon hours of play spent gathering the best gear wasted and I could do nothing about it