I think you and your hu*****and should go marriage counseling first. It is not responsible to make a devoice decision easily when you have a baby daughter.
However, you considered too much about the details of the divorce.
1. You only have about 20k saving. If they came from your parents or before your marriage, it will be yours. If your hu*****and said it was, then he will have to give evidence in the court. In fact, you can use them to pay your school expense, before the court final ruling, you actually have spent most of them. 20K is really a nothing in a divorce case.
2. If you want the custody, then you have to take her back to US, are you sure you have enough time to take care a baby as a full time student? For 20% child support? You got to know how expensive the daycare service will be in Texas, and the most important, the baby has to have adult companied at any time.
3. The custody in TX is the joint custody, that means the kid lives with one part, but other part has the visitation rights, and legal rights, Such as you could not send your baby to China without his permission.
If you two really want to divorce, finger out an uncontested agreement, it saves a lot of your resources.