I am a noncustodial parent of a 3yr old. i am paying 300mth 4 support & i dont even c my child. what can i do?

The mother and i were together for 3 years..we broke up, she moved away. we had an apt together in my name so i couldnt break the lease to move with her. while trying to work on a long distance relationship, things fell apart so i decided not to follow her to her town. she does not call me, send me pictures of my child when i ask, or tell me anything of my child. when i make an effort on my end she acts as if im a stranger, so that just makes mo not even want to communicate with her. she is engaged to be married, living all fine and dandy and i struggle to even get $3 to make it to my employer each night. i dont mean to take away from my child because i would lose any limb for her, but she knows nothing of me, and the mother could care less. all she cares about is getting my money. what can i do?