iPad started bugged in the worst moment

I've acquired MS Word on my iPad Air this week. Yesterday I finished creating word document that connected to my job. The document counts 50 pages. I didn't make a backup copy. Today I worked in my document, when my tablet bugged. When it rebooted all the work was lost. I visited some communities dedicated similar problems with hope to repair word document by manual guide or something other thing. But my efforts didn't give a result.