i got a pretty tiny one; at the time of purchase it wasn't super noticeable to me so i didnt think i needed a huge one this is the link: Dehumidifiers,TABYIK 35 OZ... https://www.amazon.com/dp/B09TSZTMZ2?ref=ppx_pop_mob_ap_share my apt is 735 sq feet
We're in Georgia and dealing with similar issues, although ours is an older home and in desperate need of a new HVAC system in addition to everything else.
We have put dehumidifiers in the main rooms and that helps a lot. Taking the humidity down to between 30% or 40% makes a difference. The rooms feel cooler. Also we bought a standalone A/C unit from Costco that my partner uses in his office during the day and then we roll it into the bedroom at night. It was about $450 but far less expensive than a whole new HVAC and it makes a HUGE difference in sleeping temperature.
This is the a/c we got: https://www.costco.com/hisense-700-sq-ft-dual-hose-portable-ac-with-heat.product.100482553.html
And these are the dehumidifiers we got (3 of them - office, bedroom, living room): https://www.amazon.com/Dehumidifiers-TABYIK-Dehumidifier-Bedroom-Bathroom/dp/B09TSZTMZ2/
Aside from all of that, make sure that you have sufficient external venting in your attic so that the hot air that rises can vent out of the roof. We added another vent fan with a thermostat and made sure that there were good clean intakes in the soffits. When the temperature in the attic gets above 115, the 2nd vent fan kicks in and pulls more air through the attic and out the roof to help keep it cool.
It's an ongoing struggle and I fear it's only going to get worse in subsequent summers, so everything we're doing as we remodel is geared towards planning for long term extreme temperatures.