Sadly, I don’t think you can get your spouse back. She/he said he doesn’t love you anymore, he wants a divorce, he is dating someone else and told you that the relationship is unhealthy. Those are four major barriers to being able to get back together. What’s maddening is that he said he loves you right up until that point, which was dishonest and misleading on his part which is very hurtful to do since you didn’t really see it coming. I’m so sorry, but I think you have to accept that it’s ending and is over.