I need custody advice

Hi. I recently went to court in june my daughters dad wanted joint custody i didnt see anything wrong with that. So i agreed. After it was granted he got a job up north in Sacramento. Now he's telling me that hes moving there and we need to switch my girl off every month. We cant afford to drive 6/8 hours every month and its just not fare to do that to her. Shes been going down to 29 palms to see him. His mom takes care of her the two weeks shes there. He will drive down here and there to see her. When shes home with me i never leave her with anyone she is glued to my hip. Pluss her baby brother is due next month. They jusy threw the, "im moving so we need to do month to month with her." On me today. I am beyond stressed out. I dont know what to do. I dont do drugs. Its me my fiance and my daughter every two weeks. I want to go back to court and get full custody but i feel likr the judge would just laugh at me. Please help i dont know what to do. Ive never really been to court other than that.