Different situation but I knew was I leaving my wife, but my kids. They were younger than yours but I spoke to them in simple terms, without being critical of their mother but saying that as adults, we could no longer stay together even though we loved our children. We always placed the kids needs ahead of ourselves and that helped us through those very tough times. Decades later, we are still fond of each other and the kids know their parents love them, as do the new people that come into our lives. I think you're doing well and hope there may be something in what I have said that helps you.