Mortgage arrears but can't pay until ex comes back with financial information.

I'm separated 3 and a half years, since my ex had an affair and decided he wanted out of my marriage. 2 children age 15 and 18, both in school and will go to college. I worked part-time through our marriage and had a much lower income than him when we separated. We went to mediation and agreed the family home not to be sold until our girls finished college, but it was never signed and he came back to me a year ago with a new agreement which asked for the house to be sold when the youngest is 18 and also that I would start paying half the mortgage. He paid full mortgage until Christmas when he stopped paying half of it, has been emailing me etc, badgering me to pay mortgage but has been very slow to respond to my solicitor's requests for financial information. I have now got a second job and have offered to pay half mortgage on condition of house not being sold until youngest is 23. My solicitor insists on financial info being furnished before I agree to anything, but we have asked for information and a meeting to sort things out. No response from ex 2 months later and I am getting calls and letters from bank. Ex sems very angry with me and especially since I am in a new relationship and he sees this man's car at our house sometimes.Finding it very stressful, any suggestions about what I can do to move things on, my priority is to keep my home?