Brittany Cartwright was granted a temporary restraining order against estranged husband Jax Taylor amid their contentious divorce, Page Six can confirm. In a bombshell declaration submitted to the L.A. Superior Court on Thursday, Cartwright described years of alleged abuse by her ex — including an instance when he allegedly threatened to “gut [her] like a f–king fish” and “f–king kill” her. She alleged that her “Valley” co-star said this during a furniture-throwing attack that led her to suffer injuries. Cartwright also claimed that Taylor, who now must remain 100 feet away from her, subjected her to “coercive control, financial abuse,…