Am I in An Abusive Relationship

Heather writes:

Hi Chauntel,

I need to know if im in a abusive relationship can u help me?
when me nd my partner first met he bought me fowers chocolate nd put money into my bank account all the time, but since he has moved house with his friend he has changed, when we argue he grabbes me by my throught nd puts me on the floor nd drags me, he has never punched me or anything like that, he says he does it because he feel threatened when we argue he feels like im going to hit him when im not it has happened on 4 diffrent occasions, but last we we had an argument nd he threw me on the floor and opened the car door which hit me in the head then dragged me nd pushed me for about 20 mins then put me on the floor again then put me on the floor again after that nd screaming at me whilst im shoved in the corner nd his friend grabbed me by the throught but when he put me to the floor he grabbed me by the throught everytime, he done this because i asked for my car back that i lent him nd now he is refusing to giv it back because he had to replace the clutch,, i dont know weather to leave him or not, but now i finch at him and im scared to speak my opinion incase he gets angry but when he doesnt do this sort of thing hes really nice too me,, i really dont know what to do,, please help,,, thankyou