General advice on life really.... trigger warning

I’m not really sure where to start to be perfectly honest... so I’ll start here... trigger warning....

Friday Night: my daughters dad was being quite frankly an Ar*@hole. We split two years ago on her birthday when I found out he was banging my best friend, the maid of honour at my wedding, my godmother to our daughter ( oh yeah, the whole hog) betrayed isn’t the word. Anyway, he has a new women (rather glad to be honest when he was single would pester me for sex all the time) she is American lives in America with her 10 year old son. Our daughter is 3, 4 in April. Anyway he has met this women once for 24 hours not seen her since but has an online relationship with her and send her money for her son (he doesn’t do this for his own daughter) I recently found out he has been sending picture of my daughter when he gets them from me to this women and allowing them to have FaceTimes and phone calls when my daughter is in his custody for the very very rare weekends.

On Friday night the first time since Christmas he “found time” to see his daughter (no phone calls no texts nothing to his daughter since Christmas despite finding time to call his gf ) I confronted him and politely asked not to allow that contact between them or photos to be sent to a women that well know one knows. Not even him. There was no malice, no misconceptions about me being “jealous” ( his words) I was clear and to the point and according to him I am “jealous and controlling” and he refuses to “obey my commands” I simply asked politely as it’s confusing my daughter thinking his gf is her “new mummy” (side note: my daughter frequently thinks her dad doesn’t love her. Although we talk about daddy being a superhero and is out saving the world that why he can’t see her all the time and having special magic teddy’s that’s go to daddy when poppys asleep you tell him about how well she’s doing ect)

Now I am in a happy engagement and expecting our first baby as a couple in October after a few miscarriages. He is well a wear of this has met my OH and they’re civil in each others company. Now After suffering a string of abuse from him for asking a simple request I’ve decide to writer a contract with a solicitor outlining the details he quite clearly misses for example: he must call twice a week and see her once a month or contact will stop and he will be taken to court. No pictures of our daughter to be sent to strangers ect.

My mum think I’m being immature and overreacting to trying to give stability to poppy. So she knows where she stand and also to protect her from random people have pictures of her in her school uniform ect. We all know what some type of people can be like and it scares me. She told me to stop being f!@king stupid (she still loves my ex and openly admits it)

Am I overreacting?

Is it me that has the problem?

What would you do?

TIA