Rain, does he have a mother or sister or someone that you get along with? If so, perhaps you could communicate through them only. If it's something important, he can have them contact you. Then, you can block his #. You should not have to read all of those messages just to find out of there is an important one in there about the kids.
Actually, what you really should do is set up a visitation SCHEDULE for him to follow just like the courts would. He can see them at those times and otherwise would have no reason to need to contact you. That way, you can block his # anyway. He is keeping you in a constant state of being upset. He is emotionally abusing you on a daily basis and you shouldn't have to put up with it.
And, btw, you are NOT the one that needs to grow up. You are doing just fine. You're just trying to get over a devastating event that has happened in your life. What has happened is horrible and excruciating, and he is making it impossible for you to have even a moments peace in your life because he is constantly spewing his self hate on you and keeping you in a constant state of upset because of his emotional abuse. You are not the immature child, he is. Don't take the blame for that!
M:45 H:48 M:11 No kids BD:Sept'15 EA:Confirmed 1wk later PA: Oct'15 12 '15 2 wk R Just kidding, H wants NC 12 '15 H back w/OW 4 '15 R &still working on it