Help with preparing enough milk for daycare!

My son is 12 weeks old and will be going to daycare in about 4 weeks. He is breastfed all day/night except my husband feeds him about 1-2 bottles, usually at night. I am starting to get nervous about milk supply because I’ve been pumping for a few months, usually twice per day, and am only getting about 3-6 oz. Extra. I have barely any freezer stash and idk how I’m going to have enough to send him to daycare with ~12 ounces of milk.

It’s hard for me to find time to pump more than twice a day because hes a big boy and drinks a lot ! 😅 Any suggestions?

I am not opposed to supplementing with formula if it comes to that but he does have a dairy sensitivity which we’ll have to navigate carefully.