If husband and wife have been separated for 16 years are they considered divorce in TX

You are not divorced yet, but there is no requirement in Texas that you use a lawyer to get a divorce. However, you might want to get the help of a lawyer if your divorce will involve children.

You should know that under Texas law, the child your wife had with another man is presumed to be your child because you were married to her at the time the child was born. That child's existence will make the divorce more complicated.

Even with children, it is possible to get a divorce fairly inexpensively (even with the help of an attorney) if you and your wife can reach an agreement about all kid issues and property issues.

The above answer is correct. However, I would not recommend proceeding without a lawyer in this case. The custody/presumed father issues alone will make this is a complicated matter.

I know that price is a concern, especially in this economy. Family attorneys offer a variety of pricing structures. Some charges less for "agreed" divorces, some have flat fees, most still use the retainer/hourly fee arrangement. Call around and find the right lawyer for your case.

Doing your own divorce is like doing your own dental work, or plumbing. You can do it, but that doesn't always mean that you should.