How to increase milk supply ?

I’m 2 weeks PP and I’m breastfeeding/pumping for baby. I manage to pump 2-4 oz out of one side and maybe 2-3 from the other. My thing is I can only fill up one bottle at a time and baby is cluster feeding at the moment and I find myself running out of milk 😫 baby gets crazy while waiting for more milk to come in. I’ve tried the lactation cookies but I don’t think they’re working for me. Any tips on how to increase my supply? I’m returning to work in a few weeks and I’d like to pump enough where baby can eat and I can also have some frozen for the future. TYIA !!