Struggling with the thought of my baby getting bigger

I don’t feel like this is normal. My baby will be one month old on Monday and since she was born, I have really been struggling with her getting bigger and growing. It just feels like she’s already growing so fast and I just want to bottle up this newborn stage and make it last forever. She’s getting close to growing out of her newborn clothes and for some reason, that makes me so so sad. I think about it constantly and how I just want her to stay this little forever.. it’s been the fastest month of my life already and I know it’s just going to keep on going faster.

I actually get upset and annoyed when people say things like “before you know it she’ll be walking” or “it goes by so fast, they grow up quick”. Why am I feeling so overwhelmingly sad about this?! Is this normal?