[Not2B]

Mmmm...

2 main things to do.
1) Reduce heat energy from entering
2) Remove heat energy

Window films will cut the sun load. (And in Texas in summer, I'm guessing you are close to 1000 watts/m2.)

Powered vent fans will help pull in cold air (remove heat). OR - if you find the return vents, fans going the other way will remove hot air (remove heat).

Insulate your room to the outside. (reduce heat from entering.)

You live in Texas. It gets humid I assume. The swamp cooler (evaporative cooler) might not be a good idea, since it requires a dryer air to really work well.

The peltier effect is really awesome and fun, but probably not a good solution for this. The average store TED (thermal electric device) is about 40 watts. A human at rest, on average, gives off 100 watts. PLUS - if you remove 40 watts from one side, the hot side has to get rid of 40 watts plus the power used to run it (lets say about 80 watts), for a total of 120 watts. Now you have a HUGE problem getting rid of all that power. And don't get me started on the tiny Delta T.... (I spent about 2 years doing research on these things. They are AWESOME, for the right application.)

And before anyone says plug in a fridge and open the door, remember that will heat the room up. It's all energy. Learn as much as as you can about energy, and you'll come up with some cool ideas. (Pun intendent.)

Good Luck!