Money Spent On On-Going Court Hearings

I am currently going through court proceedings for contact of my 3 year old son. It has been going on since November 2023. My ex partner has legal aid, even though I believe she shouldn't qualify. And as a result of her having legal aid her and her solicitor have stalled at every junction, which puts more financial pressure on my to continue to fight for my rights. I have received what I believe to be fair contact to my son throughout the year in every Tuesday 7:30am - Wednesday 5pm and every second weekend Friday 5pm - Sunday 2pm. However now I would like to have holiday contact at points through the year - which i believe i should be entitled to. I have tried to negotiate with my ex partner, via the solicitors as she is not willing to discuss directly with me, however she is failing to be reasonable. She proposed to me a 3 year plan where I get him for 5 extra days 3 times per year and had also dictated the dates I would get him. Something i refused as I cannot agree to dates 3 years in advance. All I proposed was to share christmas day every year and have alternate years where we each have him on christmas morning, and for me to have him extra 5 nights, 3 times out of the year for holidays. Now they want the court to proceed to a case management hearing because no negotiation can be agreed. I believe she is doing this just to continue things and spend my money going to my solicitor. I do not want to give up fighting for the contact I should have anyway - but the money I am spending on solicitors is spiralling out of control and I fear I will end up in serious debt. She also lives in a joint owned house that I still continue to pay half of the mortgage on, as well as paying Child Maintenance. I am currently trying to have the house sold but she will not agree to that, and is saying she will take over the mortgage but I know for a fact she will not have the affordability for the mortgage - it is all just more stall tactics so I have to continue to shell out large sums of money to her and she continues to live in the house. I have also received instructions for a tax bill for High Income Child Benefit Tax, however we have been separated since July 23 - and I cannot get a straight answer from HMRC if I am liable for this tax. I would appreciate any help or advice on how I should go forward. I am very worried she will manage to take away my court ordered contact I have fought so hard for over the past year.