Can you edit out the GF and repost the picture of you and the puppy, since you think it is cute? That would show her that you have rights too, but that you respect marital boundaries regarding old girlfriends.
Get that counseling. Tell her that it is your business and your counselor's business what you talk about. I have dealt with something similar, except that my H doesn't want me to have a male counselor, or discuss anything that even borders on s*x. I agreed to that, have a female counselor, and can talk about anything I want.
Have you read Willard Harley's book, Love Busters
? Another one to read is No More Mr. Nice Guy
. You can download it for free. You don't have to create an account, to download it at the link below. To print it, you'll need to work with your program to move the text over a bit, to make a left border if you are going to bind it. Here is the link. https://7chan.org/lit/src/Robert_Glo...r_Nice_Guy.pdf Hold Onto Your Nuts
, by Wayne Levine is also a good one. Maybe someone here has a link to a free download, or audio download where you don't have to sign in and give a credit card first??
She is disrespecting you, and treating you and the children like cr*p. When you find your boundaries and hold to them, she will either have to change, or you will decide you don't need her in your life. But first, you have to change and stop being afraid of her...even if your excuse is for the sake of peace.