Increasing breastmilk fast

Empress

My LO just turned 7 months a few days ago and my freezer stash is almost gone. I usually send 3 5oz bottles with him but lately he seem to be wanting more more milk. How can I increase my milk fast because my freezer supply may only last a few more days. I pump twice during work hours but barely get anything out. I'm stressed about this. Any suggestions are welcomed