How to handle toxic co-parenting

Hi mums, looking for some advice on how to handle co-parenting with my kids father.
Counselling services told me before I left that his behaviour fell under the DV umbrella as he was very controlling and emotionally and verbally quite nasty to the kids and I.
Apparently his anger issues aren't as bad now and he's currently acting like a Disney dad to impress his new gf who he moved in before my belongings were even moved out.
Obvious everything else is a bit rough but I'm trying to move on from the bulk of it. Every time I try to bring up a concern he gets nasty and turns it around on me, so I've minimised all unnecessary contact, which also made him angry, but now I've found out that he's been lying about me and badmouthing me to people including to our kids. He's trying to say the breakup was mutual because we didnt agree on a few things like cleaning etc (I left because he was angry, nasty and was telling me that me not allowing him to have sleepovers at his new female "besties" house made him suicidal, and I could go on), he's saying that I'm lazy and that I never did anything around the house, doubting the kids parentage as far as to get them dna tested behind my back and lie about it (even though he's the one who acted shady while I was loyal from the day I met him until after I left), that I'm selfish and take all his money so now he's so poor (he lives in our family home with two good incomes but has to pay me child support, while I'm crammed in a 1 bedroom apartment with two kids on a single parenting payment).
I'm not overly concerned about the adults he's telling because everyone who knows me knows it's all a lie, but I'm really worried that he's putting in the kids heads that I'm awful and that it'll affect my relationship with them and how they see me, especially my eldest who craves his dads acceptance.
Every time the kids come to me and say "Dad said x about you" I have to sit there and act like it doesn't break me and make me so angry.
I never bad mouth him to or even near the kids, even though he's done and said some absolutely horrible and disgusting things to me.
I can't tell him to stop it or he'll say he never said it, that I'm exaggerating or over-sensitive and just trying to cause problems, or he'll tell the kids off and tell them to lie to me again and not tell me or they'll get in trouble.
I feel so broken and alone and I don't know how to handle it anymore.