What creams or care are important for facial skin rashes?

I thought it was just temporary flushing or a few pimples popping up because of the hot weather, but as time went on, it turned bright red and spread, and my skin became incredibly bumpy. Even a slight touch makes it sting and the heat sensation is intense. On top of that, it's strangely itchy, so I keep wanting to touch it, but I'm going crazy trying to hold it in because I'm afraid it will spread further or leave a scar.

I haven't changed any cosmetics recently, and I've been eating as usual, so I have absolutely no idea why I suddenly developed a skin rash, as if my skin barrier has completely broken out. I'm so scared and worried that it might be an allergic reaction caused by a weakened immune system, or perhaps contact dermatitis.