Freezer Stash

Has anybody been able to create a freezer stash later in postpartum? I know the key is to start early but I unfortunately didn't start pumping till almost one month postpartum and that was with a single pump. Then it broke and I stopped pumping for a few weeks then finally was able to get a double pump. I'm exclusively pumping for one baby so it's super hard for me to get any to save. Wondering if anybody was able to do this? How do you save your milk when your also feeding your baby?