breastfeeding advice for preemie mom

My son is home and I want to transition from bottle feeding pumping to just exclusively breastfeeding- need help and advice on how to transition. At this point he is taking 3ounces every 3 hours or 2 ounces every 2 hours and I'm making 4 ounces every 3 hours. I'm scared my supply will drop because he sleeps a lot and especially if I attempt to breastfeed him, he's out like a light. I've been bottle feeding more and notice he doesn't want my breast after a while of sucking. He'll pull away before he's actually done eating and he'll still be hungry and I repeat the cycle of bottle pump again. Any advice would help. He was born 32 weeks 5 days and is now 1 week old corrected age. Advice please!