guppyman, welcome to ScubaBoard. There are hundreds of thousands of divers here, If you take a vote, the twenty year olds will vote out the "old folks" that have been diving 40 years. The skinny ones will vote out, anyone with any body fat. And the divers here will welcome you to our party!
Good health is important, and too much strain is bad diving form and may be too stressful for you. What do I mean bad diving form? Proper diving technique is to fit into the world of fish, not bulldoze it over. As beginning divers, all of us are excited and burn up air at an incredible rate, at the surface you can see a new diver coming with a solid path of bubbles really tumbling to the surface. An experienced diver may have bubbles coming up ever twenty feet, and may be hard to see. The experienced diver isn't holding their breath, they are breathing slowly and regularly, and swimming at a steady pace, therefore slow steady smaller bubbles at the surface.
My sympathies for your current living circumstances. With a little clean living you can move somewhere better.

There are some fresh water diving opportunities in Texas, just not great diving. Arkansas lake DeGray and lake Ouachita are wonderful fresh water diving locations. Please wait until late June or July to dive these cold mountain lakes, even then if you go below the thermocline it will be cold.
Another good choice for a new diver, is take the course and pool work at a Texas dive shop, and take the paperwork for a referral dive. to a resort like Cozumel, with all the classroom stuff done. You'll be visiting one of the worlds great diving spots, with visibility often 100 feet with reef fish and coral. Dive shops there take hundreds of new divers, on their first dives, and tens of thousands of divers into their underwater park. . . it's paradise.
At the top of the page click on the "Forums" button and watch as topics about education, new divers, diving equipment, and more, passes by, you should be reading hear for years. Way down that list is "Regional diving. . ." look down to "Mexico. . . Cozumel" and click your way in to read about People from around the world there right now, and what they are seeing. At the top of the page is a "Sticky" from a girl from Austin, that gives answers to all the basic questions. Her web site has a mandatory list of the best restaurants. . . You will be tested.
If you need more motivation to learn Scuba diving. . . click at the top of the page on "Photo Gallery" There are pictures there from all over the world, and many are from Cozumel. Welcome to the Board, enjoy!