My grilfriend hates my friend and wont let me talk to or hangout with him?

We have been daiting for 9 months now and she has always hated my bestfriend. When we started going out me and my bestfriend werent talking becouse of a fight but then when we started talking agin she got angry and is always deleting his number out of my phone. Iv tryed getting her to give him a chance but she WILL NOT. everytime i try to bring him up we fight until i have to give in. i dont want to loose her or my friend. but she has told me strate up to choose her or him. this coming weekend he wants to hangout for the first time in about 6 months.. idk how to see him without her making me feel bad or her braking up with me...how do i stop her from controlling me?