Too much arguing....help?

aghh! so frustrated! gf of 8 months seems to be very hot headed and its frustrating me. we have big fights about once a fortnight and it really gets to me. i feel its unfair as she can be very uncompramising. for example telling me off for not washing one gl ive used but missing the fact ive done loads the day b4 or gone out to the shops in the rain to pick her and her lil girl up some milk. im 24, shes 26 with 4yo lil girl and im not perfect but i try to do anything for them. and she does love me , she can be very affectionate...but also very unwilling to comprasmise. the other day i wore a chain and she said if i wore it i wasnt going out into town with her as she didnt like it! couldnt believe it. can be very bossy. anyway had mive fight last night and im low. i do love her and when we dont fight its the best ive ever had....but now im wondering if there is any point. its just the way she is. but how do i throw away something that can be so amazing the majority of times! help!