What to write???

I have been wanting to write a book about my life/divorce/craziness because I really think that people can relate. However, since my ex still isn't giving up (after almost 5 years) it's hard to write a story that doesn't really have an ending. But the it's to write something is there.  Do I try for something new, revamp something old, or finish something else?? I definitely have the time now...what to do? It's dilemmas like this that actually keep me from being productive.