question for breastfeeding/pumping mamas

I started freezing milk around September so next month will be 6 months of it being in the freezer. I think that is when it "expires". What do u do with ur freezer milk? When u feed it to baby do u pump as well to keep up ur supply? I'm considering just letting it go bad but at the same time I worked hard for it but I also want to keep my supply up. Thanks in advance!