I feel like I have no life anymore9

So here's a little bit about what's going on

3 months ago my partner and I had 2 kids put in our care, one being his son and the other who we thought was his daughter turned out not to be, he promised he would be home from work (he's self employed) by 3 to help with the kids ( I have 2 of my own one with him one not) were in a 2 bed place so there's 6 of us so it's stressful as it is It sounds horrible but I didnt want them here I the first place only because there is quite literally no room nothing to do with them at all they were put with us cause their mother would rather do drugs and left the 2 year old with a 10 year old every day

Fast forward to now

I'm so unhappy and depressed it's unreal I have no life I can't do anything or see anyone or go anywhere, I'm the one looking after all 4 kids and I'm pregnant (not planned) he refuses to do anything with the young girl because for some reason all she does is scream and cry and throw the biggest fit of her life anytime she's left with him to the point she will start throwing tables she's 2 years old, she's with me all day every day because in his words "I don't want to look after her" he's got to the point where he will literally just keep shouting at her when she has her fits and screaming and things, she's perfectly fine with me but she changes badly when I go but fine fine im back, I have to wait at home after school for his son to get back and I still can't do anything because his son will throw the biggest strop whenever you mention going out, I have MS aswell and my eldest son has aspergers/adhd so I have enough going on.. the 2 year old doesn't talk refuses to talk, if she does she only repeats the last part of the sentence you've said to her she doesn't understand a thing, I wanna tell social that she needs to be placed with someone else because I can't keep having her 24/7because he refuses to have her and its unfair on her being left with my partner to scream and cry all day until I'm home, does this sound unfair for me to suggest this

**edit**

I spoke to my partner about it and all he did was have ago at me for asking him to help out more, I had a meeting with social today and expressed how I feel and how I all making me feel and how he is with the children she agreed with me that if the little girl isn't happy with him she will arrange for her to go home and have support from them with her mum to make sure she gets the best care possible