Supply issues!

So this isn't my first bf rodeo. But it's the first time my supply dipped. Went to feed my little guy to sleep last night and he just screamed and cried wouldn't latch, finally got him asleep and broke out my pump. Nothing. Not even a teaspoon. WTF I almost had an oversupply at first (he's almost 5 months) this morning I woke up after chugging water all night and got 2 oz out of the side that had nothing. Been pumping and haaka that side all day while drinking lots of water and eating boobie bites. Any advice? I'm at a loss as to why I'm having issues I feel like he's on the boob a lot so the demand is there.