Hi @Moonbeam18
I don't often post but I have name changed for this anyway.
I am about your age (24) and 4 years ago I was in a very similar situation to yourself, the only difference being my partner and I didn't have a child together.
He had twins (1 year old when we got together) from a previous relationship. He wanted me to meet them very early on but I wanted to wait until we had been together a while longer (I.e at least 6 months) rather than on our 2nd date. The arguments this caused...apparently I didn't care and wasn't interested. This should of been the first red flag but I was young.
When I did meet his children i was overwhelmed by how much of a 'great dad' he was. He was so playful with them and seemed so loving. I look back now and I realise he never catered for their basic needs. I changed their nappies and I made up their feeds. He was just there for the fun side of it.
Anyway we eventually moved in together and it became clearer how much more I did for his children than he did. I have read your posts and I just hear myself. I paid for the trips out, the new clothes , the food for dinner. All because he was on a lower wage than me and had no motivation.
Another similarity is the violence. As long as I played ball, like I get the impression you do, everything was fine. However if I ever disagreed with him or said I had had enough it would begin. I'm not going to go into as it is too hard but trust me I understand what it is like. I have also had hands around my throat.
This carried on until the beginning of the year. I just put up with everything, isolated from all who loved me and scared to leave for various reasons, mostly his amazing twins for the reasons you have stated after all who would look after on his weekends if I wasn't here?
At the beginning of this year I got diagnosed with PCOS and due to various factors (now haven't had a period for 13 months) I have been told it will be unlikely I can conceive naturally. Once I got over my sadness I took a look at my life and realised I was wasting it with my xp.
It has been hard and I have been heartbroken but 6 months on and I am so happy. I am me again. Away from the violence and the moodiness and the treading on eggshells. I also made contact with the twins mum and despite her (understandable) hostility towards dickhead ex she has recognised my care and love for them and I still see them.
This has been a very long post but I want you to know that you can escape this and you can be happy. In fact you will be happier without him. I know it is more complicated for you as you share a child but you and your child (And step child) deserve a non-violent happy life. I just hope you know that.
Sorry for how long this was....it has ended up being massively cathartic lol! If you want to pm me feel free. I wish you the best of luck. X