Lost boy oh boy

I feel so confused and just at a loss for what to do anymore, I am 23 years old I have two biological little girls and 3 step kids my husband is 33, we are both previously divorced and I feel like it’s coming down to us splitting the same. He is allowing his ex wife to sway his anger at me over something so stupid, me and his ex got into an argument due to him wanting to change their weekly schedule to work out better since we have 3 kids in three different schools and all

different work schedules she got all pissed and it ended in me and her having a phone battle. “ stupid I know!!” She says she doesn’t feel welcomed at our home so she doesn’t bring the kids by when she has them for example, she had them for Halloween and brought them to trick or treat around our neighborhood his youngest daughter by her had to pee instead of her bringing her to our home right down the street she made all the kids leave early and go home ( her home) he was upset they didn’t come by for candy and she texted him saying she doesn’t feel welcomed by me! He started yelling and cussing at me because she allows childish shit to rule her actions I simply don’t speak when she is around momma always said if you can’t say something nice then don’t say anything at all, and I truly can’t talk to her she has tried pleading with him to let her come back that me and him having a child together doesn’t change anything I can’t trust nor want to even talk to someone that sneaky she has ruined my relationship with my step son he doesn’t even talk to me without being rude anymore. I feel like I’m going to lose on both sides he is demanding I be friendly with her and I simply want no parts of her at all they don’t need me to co parent that’s their job her fiancé stays quite and out of the way but it’s an issue when I do the same. With everything about him turning on me to please her and all the bull crap he is letting his ex wife turn us against each other what can I do.