Yes, a family Court Judge can put you in jail in an enforcement action for not paying while you were incarcerated. Start making payments toward the arrearage now, which will make you look better when you are in front of the Judge.
Also, you should be aware that not paying child support is often a probation violation in Texas. Check with an attorney in your area to see what your exposure is.
Yes you can get locked up for not paying your child support. If your wages have changed since the initial order, you could ask for a reduction accordingly.
I am only licensed in Arkansas. No part of this answer should be construed as creating an attorney client relationship.