N.
We have the same problem. We got solar screens from Lone Star Solar Screens based in Irving this spring. It has made a HUGE difference to the temp upstairs until the triple digits hit. Before the screens it got up to 85 upstairs, now it is 82 and the AC is roaring. If the temps are in the 90's it stays cool to 78 upstairs. Once the triple digits hit, it doesn't make a whole lot of difference. Residential AC's (even the good ones) can only cool to 20 degrees lower than the outside temp. So with it being 107 outside right now, I guess 82 is not bad. Good luck!