I have family in Lake Travis and when I was first diagnosed my sister in law and I looked on line at the time. There are not a lot of options but I did find this-
/www.txlda.com/ The link is for the Texas Lyme disease Assoc. You can contact them and they will provide doctor information.
I also saw that Texas A & M has a Lyme Lab. If they are doing a study that you can get into that would eliminate your costs concerns. I recognize how far that is for you. UT may also have a study-it's worth looking into.