joint custody

Me and my 7 month old lives in Missouri, and her dad lives in Texas. I got pregnant in Texas but I went back to Missouri as soon as I found out I was pregnant ( I was a college student at the time) long story short me and my ex where in a long distance relationship I've been taking care of my baby physically by myself , he's came to visit twice and we flew out there to visit twice. He hasn't really made any effort to come see her or be around her more . He was ordered to pay child support without my consent because unfortunately I'm receiving government assistance, now he's mad saying he doesn't want anything to do with me , and that he's taking me to court to get joint custody. How will joint custody work if you both are living in different states ? Is that even possible especially with a bay involved?