9 wk old falls asleep

Baby is 9 weeks. He has pretty much always fed from both sides at night. He gets drowsy after the first side so I change his diaper to rouse him enough to finish. All of a sudden in the last couple of days he is absolutely refusing to wake up after the first boob and do the second. Blowing on his face, rubbing his feet, even wiping him down with a wet cloth don’t make a difference. This means he wakes up again 30 minutes later to eat again, not to mention me feeling engorged in the ignored side. I’m losing my mind from not sleeping. Why is he doing this and how do I fix it?