I'm in need of some advice regarding exp and how things should be moving forward.
Going to mediation tomorrow and have a few things I'd like to discuss but mainly child maintenance
Back story...exp stopped paying child maintenance last Christmas because he was pissed off that DS wouldn't be with him on Christmas Day. He then refused to pay anything for a further 6 months, quit his job to avoid CMS and only now pays as I (quite rightly) refused to discuss anything until he agreed to restart payments. He is suitably well off, and does not struggle financially
Before this happened, he told me if I didn't travel to collect DS every weekend he would withold CM. And then got asrsey if I said no and point blank refused to return DS. I Told him to contact a lawyer so we could get it all sorted out properly and contact would remain the same once it was sorted. I was tearing my hair out with stress over it all at the time and anxious to the point of being unhealthy. I was working part time and couldn't even make ends meet. He lodged a court order demanding DS should live with him 50% of the time and said if I agree to DS going to private school...he will pay CM as a 'goodwill gesture'
His demands were ridiculous and also asked to have DS every single weekend. He didn't get that obviously but DS only gets one weekend with me a month, and one Saturday
Fwiw....exp has many many flats which he rents out, and also had a very well paid job but has since quit his job so CMS could not get him to pay a penny and he was able to hide his rental income. He doesn't need to work and lives off the rental income. (He told me he would do this when I was pregnant, if I ever contacted CMS. and also after having cheated on me throughout the entire pregnancy and dumping me when 6 months pregnant) trying and failing to not sound bitter here 
So here is my issue...the amount of cm exp pays for DS has never changed. It has never actually even come near to the amount I pay out in childcare. DS is getting more expensive the older he gets and although he starts school next year, I'll still have after school care to pay for. Exp is almost 40, I am in my twenties and my career is only just beginning to take off, so quite a gap in terms of being financially established if that's of any importance.
I'm wondering how other people work around this. Has the amount stayed the same since birth, or do most exp's agree to up the amount? (I realise there are plenty of exp's who pay nothing, I'm sorry if you're reading this and that is the case)
This won't go down well with exp. he is already telling me again that I need to start travelling to collect DS at the weekend despite him being told by his lawyer that it is his responsibility and he has been forceful via text about how we must discuss this out with mediation. (In order to bully me) he thinks I ought to be grateful that he pays cm in the first place. And he buys his own clothes/shoes/jackets for DS and keeps them at his place so doesn't contribute to my expenditure in that way.
How can I argue my point, I struggle with this. Or is it even worth rocking the boat? He will at some point try to get away with not making payments if he thinks he can get away with it, and would like the payments and travel arrangements to be put into a minute of agreement but my lawyer says only contact arrangements can be put in there
Can anyone help me?