Am I a Dead Beat?

I pay child support every month but I dont ever see my kids, she changed her number and moved, she lives in the next state and I just dont have the money to take her back to court, cause I know she is gonna fight me, I have joint custody and the last time I picked up my kids 4 years ago, I had to call the police to have her release the kids to me, maybe this is just a dumb question to ask, I am just not strong enough to go through it again, I love my kids and think about them everyday and I have even tryed writing but no response. She was even arrested for beating my azz, I never pressed charges because she was my wife at the time, I divorced her and just started my life over next state over but I am still missing my kids in my life, I am only 26. Maybe I will wake the hell up and just take that chance and go to court and get those kids back in my life. This girl really screwed my head up.