lost the child to whom?
This question cannot be answered. There are simply too many facts about the situation that are not known.
Do you have a court order saying you have visitation? Are you the biological father? If so then YES. Go back to court and file for custody.
TEXAS WANTS FOR CHILDREN TO BE RAISED BY THIER BIOLOGICAL PARENTS.
The mother has presume sole custody and control, regardless of the circumstances in all states.
her choice
Properly, yes, however there can be complications. If the mother names some other person guardianship, the father could be facing an expensive custody challenge. This issue should be clarified in the custody orders. see links below
Your mother will have to request a change of custody. You cannot do it yourself.
see links below
This is a problematic area and cannot be clearly answered in that Juries can be used in Texas to decide custody. It's the only states that does.
Yes, if the father is not given custody he will be obligated to keep paying support to whomever the court awards custody or guardianship of the children.
If Mom has custody then she gets to decide where you live. You can move in with Dad if Mom agrees to it. Otherwise, Dad would have to petition for a change of custody.
Yes.Yes.Yes.Yes.