Yes, you need to file for divorce and obtain a signed divorce decree and then wait the statutory period of time before being able to remarry a new partner. If there is not significant property or children it is a relatively painless process as long as you have an address for the other person and they are agreeable to getting out of the marriage as well.
While we have common law marriage in Texas, we do not have common law divorce. You must file a petition for divorce in the county where you live and complete the process before you can marry another.
You are married so now you need to file for divorce. If its uncontested it is not expensive if no minor children are involved. You might try one of the pro bono (free) legal services and see if they can assist you.
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