leaving my partner!!?

So I've been with my partner for just over 2 years. Engaged and we were ttc
He has 2 children from previous relationship and I have 1. 
We have always had dramas with his kids and mother. I do everything for his kids and I get treated like absolute shit from them. 
And my partner would go through his moments, calling me names etc. we argue all the time.. I've said before I would leave but when I moved in, I got rid of all my furniture etc I had from when I was living on my own.
So I was trapped basically, no job, an hour from my hometown. No one around me.
But I finally had enough! And I've got everything sorted to move into a friends place til I get back on my feet etc.
Only thing is my car isn't in my name yet. We sold my car for another car and everything has been in his name so far. 
I've been so distant from him lately and he knows it. My dad told me to get the transfer papers for this new car I just got and then leave. He knows I'm not happy here at all and I'm not myself.
My partner has asked me if I'm just staying to get the car in my name and then leaving. I've had to lie and say no. And I feel absolutely horrible for it!
I don't care about materialistic things, but I came with my own car into our relationship so I need to have 1 to leave?
And I finally it the transfer papers for the car, but I know he's going to hate me when he knows everything 😞 I love him but it's all just too much for me to stay!
He promises things and then goes back on them our whole relationship..
I'm not sure what I need from u ladies, I thought no I just need some support and motivation.. and words to help me not feel so bad :(
UPDATE:
The car is now in my name after a lot of struggle! Now just to leave. If I leave while he's home, he will make me stay so I have to wait til tomorrow when he goes to work and I have the whole day to move..thank you ladies for the support :)