Welcome to hell. But, hey, it ain't so bad. Lots of us nailed GTT (Gone-To-Texas) on the cabin door when things got too hot back home. That way no one will prosecute us... Not after we picked our own punishment. Like Kipling said, "The scenery is good if you're in trouble."
Fire ants: OK if you have the gumption to not camp on nests. If unavoidable, put out sacrifices of cracker crumbs with tablespoons of cooking oil at corners of camping area. I don't bother with a floored tent except in developed campgrounds. Wouldn't get caught dead in one of those. They are not much trouble in the backcountry except canoe tripping and staying on sand bars.
Mosquitoes: Even one mosquito is bad, so the fact that they aren't as bad as Canada or Main or Minnesota is no help. Except near the coast. Nothing short of mayhem stops a saltwater mosquito. Not DEET for sure. Some folks swear by rancid alligator fat. Others use bug suits treated with permethrin. Kill them suckers. Bug net is good.
Snakes: Don't worry about them. I've seen more per trail mile in NY, Penn, and even New Jersey than in Texas. Just carry an Extractor kit. Rattlesnakes are favorites. They go off like smoke alarms when you get within 20 feet. That's pretty exciting. Can't tell where they are at first.
Heat: Hammocks make it practical to backpack in the summer east of the 98th longitude (Dallas to Corpus Christi, more or less). Otherwise, the humidity and heat will kill you. Really. Hammock siestas in the afternoon - until 3 or 3:30 are highly recommended. In West Texas and New Mexico the humidity is not a problem. That's good because there is nothing tall enough in West Texas to hang a hammock on.
The neat stuff: You can backpack all year round. 3-seasons for everyone else is 4 seasons for us... except we don't have seasons. A 40 degree bag is 3 season here. You can leave the sleeping bag at home all summer. But take a hammock. Rain doesn't last long...15 minutes is about average. Of course, that rain will be a monsoon with tornados and hail, but the farmers always need it. I've seen snow, I think.