Is it sad to feel old at age 27 or similar?

I'll be only turning 27 on the 16th. I feel like I've always been old.

Older sister to 20yrs,11yrs,6yrs siblings. Been in same monogamous relationship for 9 years, I'm old ladyish when I want nothing but my cat snuggle me and watch Netflix after work..

I feel like I should be exergetic and happier but I'm just feeling down. Anyone else feel the same about their age/life?

I Know I should change the things I'm unhappy about but I just couldnt care anymore about motivating myself to make those changes.

Oh well.