I really need to vent!!

I am so down and just cry all the time at the minute.

I am a full time mum to my 3 children who are 7,6 and turning 1 tomorrow. I am also 26 weeks pregnant.

My partner who isn't the dad to my oldest 2 is so stressy lately with my older children, he's forever getting on at them and I've told him countless times to stop it's not fair it's as though they cant breathe without getting shouted at lately.

We had somewhat of a talk tonight about it and he says that he's not happy. He's not happy because my kids don't always get on with him, and I said maybe if you didn't get on at them as much then things would be better. He hates it that even though their real dad is an absolute arsehole that let's them down constantly and doesn't pay anything towards them, they still love him. Which they're bound to do, hes their dad at the end of the day. They don't understand what being let down or not getting any maintenance from him means.

It is affecting our relationship. He says he loves me and that's why he stays but if I'm honest I'm not happy either.

I don't ask for a lot from a relationship. Money means nothing and material things neither. All I ask for is time, honesty and to make me feel wanted.

For 90% of the first two years of our 'relationship' he lied constantly, hid things from me and kept going back go his ex who he also has a child with. I took him back time and again with him begging for me to take him back. What I thought was the final straw for me was in may 2019. He left and moved back with his ex. I was totally done. But somehow I ended up taking him back.

he really has done well this time in the sense that We have been together for 6 months without him leaving once. But I get really insecure at times when it comes to him having contact with his ex and in my mind its rightly so after everything that's ever happened and he should continue to reassure me that everything is okay. he thinks I shouldn't have a reason to not trust him and even though he told me when we first got back together that he would reassure me no matter how long it took he says now he's got to the point where hes fed up of it and it's getting him down. I get it to a point, a relationship cant work without trust. But I find it so hard to do. No matter what I do I don't think I will ever be able to get over it. I don't think I'll ever be able to trust him. He broke my trust countless times over and over.

When I say I dont ask for a lot, all I really want is to be shown love and cared for. If I'm down about something all I ever want is a cuddle - really it's that simple and I have told him this over and again. But I am here again balling my eyes out at nearly 4am and cant sleep because I feel so unhappy and a simple cuddle would make me feel a whole lot better but he is literally a million miles away at the opposite side of the bed that if he moves one inch hell be on the floor. You could get a jumbo jet between us.

I really think the best thing for me and for my kids is to leave. But being 26 weeks pregnant with a high risk pregnancy (placenta previa) I am on strict instructions for no heavy lifting or exertion so packing a house up and moving with 3 children and no family to help or support us is near on impossible.

I'm stuck

EDIT

He is really good at making me feel like I'm overreacting and says that if kids dont get told then they'll carry on. His style of parenting differs completely to mine but I have expressed my feelings time and again to him about it and he just gets upset saying fine let them do what they want and saying he'll just not get involved in the future..