There isn’t anything you can do legally to stop a divorce if your spouse wants it. You can’t keep someone in a marriage if they don’t want to be in it.
Notice that I said you can’t do anything “legally.” I’m certainly not implying that you do anything illegal, but you can always try some non-legal options.
The most obvious option would be to try to convince your spouse to try marriage counseling. Again, you can’t force them to do something that they don’t want to do, but it’s worth a try. Here’s a good resource for finding marriage counselors in Austin.