How to get custody of your child?

Texas does not have a "legal separation", per se.  You either get a divorce, or if you were not married, you file for a suit affecting parent/child relationship (SAPCR).  Before you file for divorce, you should at least do a consultation with an attorney about any unusual issues.  For example, you mention not wanting to leave your child in your husband's care.  You will need to develop facts which justify supervised visitation, because Texas law favors joint custody.  Your next step is to develop a plan on how you are going to take care of yourself and your daughter.  If you are going to ask the court for custody, you'll need to be able to demonstrate that you have the means physically and financially to do this, especially if he decides to fight you for custody.  Your third step is to file for divorce.  Depending on your situation, you can ask the court to enter temporary orders which require your husband to pay child support and which grant you "managing conservatorship," while the divorce is pending.  If you don't need temporary orders, you can just wait a short period and try to finalize your divorce asking for the same things (custody and child support).  In your final decree you'll probably want to have you both named conservators, but you want to be the one with the right to designate where the child will live.  This type of conservator is called the "managing conservator."  In addition to custody matters, a final decree should also divide property, assets, and bills.  How this decree is worded will affect you future property rights and custody rights, so it extremely important to have it properly worded.  Many divorce attorneys will do an inexpensive consultation with you.  At the very least, you may want to attend a free legal clinic offered in your area.