Closure. A detested word, yet when it comes to relationship breakups, we need it — When my ex-husband and I split up, the strongest emotion I felt was relief. Sweet, blessed relief. However, it didn’t prevent him from renting that space in my head. The space where all the ‘what ifs’, the ‘I should haves’, the ‘if only he’ds’. All. The Goddamn. Time. Even after…