How to get a supply?

I had my son on Dec 3rd Nd due to low blood sugar I didn’t get the chance to try and breastfeed. My nipples are huge, like he struggles to get his tiny mouth over just the nipple. My daughter had this issue as well and I didn’t get to breastfeed.

Even if he can’t latch on, I want to at least pump. So yesterday I started using the hospital’s pump every 3 hours. I was able to get some of the clear stuff (forget how to spell it), but not a lot at all, barely covered the bottom of the bottle. How can I get more? I don’t want to rely on formula.