You might research Fathers for Equal Rights (FER) aka Texas FER (TFER). Any branch MAY be able to make referals to other parts of the state and/or otherwise advise.
In the very distant past the branches/network were located in Dallas, Austin, Houston, Ft Worth, San Antonio and another began in Longview/Tyler. Dallas FER exists today. Expect a membership of men and women focused on the children and shared access. Much like SPARC.
Good luck