EX WIFE IS TURNING MY KIDS AGAINST ME AND I NEED HELP !!

Im looking for some advice in regards to my situation with my ex wife and my 2 daughters aged 11 and 13 I have been feeling lately that my relationship with my daughters has been picked away at by their mother (my ex wife)!! Little back story me me 31 m and her 29 f separated back in 2019 after she accused me of rape and abuse and other such things in that category all to cover up her affair with what I thought was at the time a really good friend, took me a long time to get over it based on this utter betrayal but thats that. we went through the family courts and I get less than equal custody even though all her allegations and lies were proven false! Now fast forward to about 12 to 18 months ago where my daughters come to me telling me that their mother has upped her game from emotional to physical abusive yet no one believes them, so feeling like I am the only one that can do something I start searching up on line what my reaches are as their father and the position im in with the court order and pretty much all says that im just to make reports to the relevant authorities and they will deal with it well 3 months pass and I hear nothing except my eldest daughter saying that a social worker had phoned her mum and told her what had been said which if you can tell where this is going infuriated her mother and made everything worse and increased the frequency in which they were being abused now their mother isnt exactly a smart woman but shes not stupid she knows all the little games and methods that she needs to fool people into believing that im the aggressor and the "sour ex", after all the reports and eventually hearing back from the social services team their report consisted of well although there has been an accusation of abusive it doesn't reach the threshold and the kind of abuse that we would investigate! My daughters come to me much later and beg to ti not send then back to their mums because of this ongoing issue however to save jail time I keep to the court order even though they are in tears begging.. well I explain simply that the last thing to try would be getting it in back of a judge and essentially pushing for them to actually hear from the children about their experience with their mum and then the courts deciding on what should happen! My final stand in my attempt to help and protect my children! Well as you can imagine from this the first notification that my ex recieved about the courts shes completely flipped the script now and is essentially being the doting caring and loving mother taking them places buying them things and to begin with they saw right through it and didnt care they just wanted to and only me until recently because im tired of taking the attitude and crap behaviour from my children ive decided to step up my discipline and tell them that im not having it anymore in which turned into a huge catastrophic failure because now neither of my kids want to see or speak to me in all of this ive spent £11500 on courts and solicitors fees im living on a sofa because nowhere will help me and I dont have savings I dont pay child support because the agency who determines if I do or not has determined that because I have my children over night so much I dont pay anything!! I have given my entire life to my children scrimped sacrificed and done what ive had to as a parent should for the best of my children and always to the best of my abilities but now im mentally and physically drained I have no more fight or give in me and im genuinely at the point in my life where I just sign my parental rights over to their mother and wash my hands of it all pay the child support and that be that .. allowing them to at whatever age if they decide to come and find me .. im genuinely so done with this situation and im starting to think that maybe my kids would be better off without my intervention!! Ive probably missed a load of details but im lost and I dont know what to do anymore 😔