Actions reveal a person's true nature. Words are a dime a dozen. Do you have any boundaries in place with your ex? Maybe tell him you will only speak to him regarding the children, and that's it. He may text you, but you aren't obligated to respond. I know it's hard to not engage, but with time, you can stop that itchy trigger finger on the send button. Are you in Al-Anon? The double-coverage of meetings and therapy really helped in my early NC days with my mother. Obviously your situation is different since you are exes and have a child together, so that's where the boundaries come into play.