@VeganAvoToast
Ex has just said if I do the driving I can come get ds.
This was never about ds. This was about driving. I can't believe it. All of this, and it boils down to nothing more than driving. One minute he's enrolling him in schools and taking him to have a look, next it's you can collect him if you do the driving
No its not about the driving or the schools.
Its about him coercively controlling you and using your son as a weapon in that.
How long has this been going on and how much court involvement over custody is there?
You need to 'get smart' with this. You need to detatch yourself emotionally from all your replies and not take the bait when he is a twat. You need to start documenting EVERYTHING - all the unreasonableness and all the game playing and head fucking.
EVERY time you respond, you need to think 'how would my reply look to a third party' instead. Because this matters.
You need to start thinking about formalising your child arrangements through the courts, if they are not already, and if they are start making a point of when he breaks the order (like noting when he doesn't return your son on time'.
Think about what is in the best interests of your child at all times - mucking about with when he returns for example.
You NEED to seek proper legal advice now EVEN IF YOU GET YOUR SON BACK TODAY.
This has gone beyond a normal problem and is into your ex trying to control and abuse you.
Lots of people on MN who can help talk you through all this. But make sure you fully understand what coercive control is - and how important it is you DON'T tell him that you think he is trying to coercively control you (there are legitimate reasons for this which you should see explained if you look up coercive control)