You need a lawyer.I’m not saying that because I am a lawyer myself. I am saying it because so many of my clients have come to me after trying to represent themselves, and getting a raw deal from the courts. Your case is not straightforward. You know your ex is talking nonsense, but you will need to prove that to the judge. You need to get her to define her case in such a way that you know precisely what she is saying, and so she can’t ‘change tack’ when it suits her. Once you are certain what she is saying, you then need to get every document possible to disprove her case. If you have the money, get a solicitor who specialises in divorce law. If you are a bit strapped for cash you can instruct a barrister directly which is cheaper. Either way you must have a lawyer. Best of luck.