The end of Karin Nelson’s 20-year marriage marked the beginning of her self-love affair.  But rediscovering herself after two decades of identifying as a wife hasn’t been a cakewalk, Nelson, 47, from Salt Lake City, Utah, told The Post. “I was so unhappy in the marriage — he was cheating on me, we didn’t communicate well, we didn’t always get along — but being married was the only life I knew,” said Nelson, who became a divorce recovery coach after throwing in the towel in 2017. “Asking for the