I lived in Houston for a while, there used to be several HUGE dive stores there and a bunch of smaller ones.
Lake Travis maybe
Flower Gardens (clearest blue water I have ever seen)
Stetson Banks (usually not especially clear green water)
Rigs over in Louisiana
TS Texas Clipper
The Texas Clipper is a 473 feet long artificial reef that was sank in 2007. The Texas Clipper lies 17 miles off the coast of South Padre Island in approximately 136 feet of water.
divesouthpadre.com
Take a drive on a long weekend to Pensacola and dive the Oriskany and some of the other wrecks there. For example:
From scuba diving certifications, diving charters, to diving gear repairs, MBT divers offer professional scuba training and gear for everyone.
mbtdivers.com
There is also this, I have not been on it:
A 371-ft cargo vessel named Kraken has been scuttled off Galveston, Texas to create a new artificial reef for fishermen and divers in the Gulf of Mexico. The Texas Parks...
gcaptain.com
There have been numerous reef building efforts along the Texas coast to boost fish production. The fishng industry has essentially scrapped the bottom clean of reef structure which then depletes the nursery opportunities for snapper and other (game) fish. Yes, long ago there were banks, soft rock, sandstone and hard ground covered with fans, whips and soft corals and occasionally clear enough water and shallow enough to dive. For the most part, that does not exist any longer.
There may also be another option. There used to be value priced fares to Cozumel and we would run down for a three day trip like some people go to Walmart, but, these days, who knows anything.