Shit happens and this is the worst sort, so bloody emotional and point scoring

I have been there twice and approached it differently the second time, but be warned that solicitors earn their living from these cases so be aware of this.
The first time I fought tooth and nail to have access to my two boys and not be a burger dad, I managed to get them 3 weekends out of four, it was important to me to see them asleep and have a normal relationship with them. It worked while they were younger but all the emotion had an adverse affect as they got older and became aware of the still underlying tension. My ex remarried and then came the 'we do this with you what does he do etc' It was a fatherless bloke who wanted to have a nice ready made family, well with all the pressure on the boys I saw them less and less. First the eldest at 15 turned to me and said I don't have a dad I've got a step dad, not seen him since but at the same time the 13 year old fell out with his brother with the situation and came to live with me not to see his mother for the next 10 years Now I don't see either at 30 and 27 but are kept up to date with their lives from their stepbrothers. NOT a nice situation and I helped put them through it with the best intentions at the time.
I remarried had two more boys and divorced after 3 years, rebound wanting back what I had etc. So I changed tack, did not use a solicitor and just went along with all the lies that were thrown at me. I did not fight for access nor residency, in fact I just let them get on with it. The outcome was the complete opposite of the first case, I was awarded joint parental control and social service and the court ensured that I had access. The kids came regularly whenever they wanted, arranged with social srvices so I did not have to battle with their mother I did not play mind games with their mother just accepted that when I turned up to pick them up as arranged they were not in etc etc. They both came to live with us at different times left when it suited and now they are 23 and 19 we have brilliant relationships, keeping in regular contact weekly phone calls and popping in to see the old man whenever they get the chance, going out as a family group with the grand kids etc.
That is how it happened for me, I hope you find some comfort knowing that a lot of us have been in this awful predicament and believe me in my case the second course of action was a far better way, less stressful for all.
Whatever you do I hope it goes well for you, but whatever you do it is a bumpy ride, and that is without the CSA.