Dear Jane, I left my husband four years ago when I met the new love of my life who I am now married to, but every day I realize what a terrible mistake I made, and I would do anything to turn back the clock. I am not exactly unhappily married, but I know this isn't what marriage should be, and I am burning with regret over leaving my former husband, who was - I now know - the true great love of my life. He is with someone else now, and my current husband would be devastated if he...