Is this a normal amount of breast milk!

So I wasn’t planning on pumping at first, so I was letting my milk dry up. But then I decided to give pumping a try (my daughters in the NICU so I can’t try latching her yet). The first day I pumped 20 mins like the nurse suggested and I got a lot of milk. Almost filled 2 bottles like this.

Then I unfortunately couldn’t pump at all because I was admitted into the hospital and I was on heavy medication all night.

Well this morning I tried again. I only filled about half this morning and ever since then, I’ve pumped every 2 hours and my supply keeps going down and down to now this (this was pumping for 20 mins).

Is this normal? What can I do to get my supply up if not?