Pumping

I'm trying to build a freezer stash. I use to get at least 5oz each time I pumped but I stopped So now I'm not getting much and would love to get back to where I was. So last night I single pumped every time he ate (every 3 or 4 hours, 5 at most) for as long as he ate. He would nurse on one side and I'd pump on the other. All through out the day today I double pumped every 2 hours for 10 minutes. And I would single pump for as long as he ate. How long until I notice a difference? I'm only getting 1-2oz each time now. So I've gotten 13oz total since last night.

I can't seem to fully empty my breast when I pump either.