What could be the reason my skin suddenly became dry and dull?

I felt that my skin looked unusually dry and dull lately.
I'm using the same products as usual, but my makeup doesn't have the same glow as before.
I'm not sure if it's a lack of moisture or if dead skin cells have built up.
I thought I needed more moisture, so I applied a generous amount of cream, but it actually felt heavy and stuffy.
It’s even more confusing because my skin feels dry on the outside but vague underneath.
I was frustrated because I didn't know the cause, whether it was due to the season or my lifestyle habits.
I'm also wondering if changing the product is the right choice.
How should I set a standard when my skin condition deteriorates?