Saving milk and BF???

Anyone building a stash but also breastfeeding their baby via boob? Any tips!??? I am going to start school soon and I’m soooo tired already but I think it’s important my son continues to have breastmilk, he is 5 months. I already use a silicone sucker to catch any excess milk on the other boob, but it isn’t enough to build a stash. Should I start getting up at night and pumping while he’s asleep? It’s difficult to use a double electric pump when he’s nursing too because he gets distracted.

HELLLPPPPPPP