Exclusive pumping, help please

I am exclusively pumping after trying for 4 weeks to breastfeed my daughter. She is tongue tied and will not latch correctly so leaves my nipples bleeding every time. I’ve tried nipple shields have seen a midwife etc.

I see other mums who EP with a huge freezer stash of milk and it really disheartens me because I only just pump enough for what she eats. How do you build up your freezer stash? Please can someone just give me any advice on exclusive pumping in general because I’m really considering switching to formula as I’m so upset that I feel I’m not meeting her needs.