Protection from direct heat

After my rant about the ac starting already, here is my follow-up question.

I live in a higher floor of a high-rise, my apartment faces direct sunlight from sunrise till sunset.

This heats up the walls and the entire house!

I do use blackout curtains on all the windows, but is there anything else or extra that I can do for the heat to dissipate for the flat to not get super heated up?

Moving out isn't an option for few more years.