His behaviour has effected our sex life for a long time
Who can blame you OP, who'd want to shag someone who treats them like that?
There's no fun in all this for you, it sounds awful. 
The kids don’t seem to notice his moods
I'm sure they do you know. At best, they don't know any different so think it's normal.
My dad was like this and it was very damaging due to the level of anxiety caused by walking on eggshells so much. I've never been able to work.
It will also effect their expectations and behaviour in relationships.
hes very dependent on me for everything
My mum and dad split up (thank fuck) when I was about 18. My dad mysteriously managed to get a grip once he was single, because he had to.
if he hasn’t eaten all day he’ll try and make me feel bad about it. I don’t
Glad to hear it.
What do you do to make them realise how much of a wanker their being?
I think they hardly ever admit it, or if they do they'll claim they can't help it, or that it's their partner's fault.
he’s already said incase of separation he’d want 50:50 how he’d ever cope 50:50 is beyond me considering he loses his shit after a couple of hours alone with them.
I'm not an expert, but I imagine if it does start out as 50:50 his side will reduce fairly soon.
your not the first on here to suggest his behaviour as abusive
Of course it is- your life is overshadowed with his being an arsehole, plus he's sexually coercive.
I’m not sure tho if it is abuse I must infuriate him because he very rarely gets a rise out of me
Just because he doesn't get a rise out of you doesn't mean it's not abuse. And it's not because you infuriate him, it's because he's a wanker. He has some sort of personality disorder, or at the very least wanker disorder.