I really can't take it anymore.
Backstory is we have been split since DS was a baby. DS is now 11. I agreed to 50/50 back then, which I now bitterly regret. I was young and still in love with him etc. Since 50/50 has been the case for so long and the age of DS, I doubt it could be changed now without great difficulty. He lives with his mother who does the vast majority of his parenting tbh.
Ex has never been able to discuss anything as parents. In his mind he is always right, never wrong. He will shout over any opinion or view I have, calling me 'stupid' or insisting he 'as his father knows what is best for his son'. He will shout over me and hang up. He used to threaten to take him away from me but has stopped that now as DS is old enough that DS himself wouldn't accept that obviously.
This has permeated everything, from school choice to haircuts to diet to shouting if DS sees my family to him driving him around without a car seat when little.
I literally feel as if I had a child for him and his mother to raise.
It's even worse with COVID situation in the country. He apparently 'doesn't believe' that the virus exists.
I'm so worn down by it all. I'm sick of being shouted at and undermined, and most of all I worry that I can't protect DS how I feel I should be able to.
How do I deal with this??
DS won't stand up to his dad at all, and sometimes if he gets in trouble from me for misbehaving for example I take away his gaming, DS will say he's going to "tell his gran" 
.
How the hell do I deal with this??
I've been told by two different solicitors that unless I could prove his dad is incredibly unsuitable (for example an addict or physical abuse or something), then with the age DS is and the length things have been 50/50, the court will just keep the status quo.