I know this is for breast feeding but any advice would be wonderful

I'm a stay at home mom, and I exclusively pump for my little guy. He's only a week old right now and drinks up to 300mls a day (I'm rounding up a bit) I'm also pumping over 1000mls a day. So if he drinks say 300 mls a day currently and I pump say 1000 even a day, how long should it take me to build up a supply to make it to his 6 month,, or how much would I need to make it to 6 months. I plan on switching to foods at that point and want to stop pumping soon as I can cause I'm already over waking up in puddles of breast milk and my boobs have grown at least 2 sizes in a week. ***updating... So I asked ho much I would need to make it to 6 months.. I can switch to formula then as. He needs around food.. I only needed advice on how long it would take me to build the supply to 6 months...