If I live in a desert 🌵 why the heck is it so damn cold?

Deserts are dry, not necessarily hot. When the air is dry, there is little water vapour and hence no clouds. Water vapour and clouds retain heat during the night. So when the sun is shining, there are no clouds to absorb the energy and you will feel the full effect of the sun's radiation. At night, when the sun is not shining, the heat will dissipate from the earth very rapidly, there being no clouds or water vapour to contain the heat. Think of the clouds as a blanket.

Deserts reflect heat, but don't hold it as does dirt. So, on warm days, it will seem much hotter, but on cold days it will feel colder. Deserts are traditionally very cold at night because they don't retain heat from the day.

Deserts have a more extreme range of temperatures, because they contain so little water vapour, water has a really high specific heat capacity, meaning it takes a lot of heat just to raise it a degree or so.

So places with higher humidity and moist soils warm up a lot slower, and also cool down a lot slower.

A desert is a desert because it is dry (typically, <10" of rain per year), not because it is hot. The Gobi, for example, is a "brass-monkey" desert - - in other words, very cold.

Deserts are dry. They do not have to be hot

it can get very cold in deswserts especially at night times