hey momma! Good job sticking to what you beleive in!
2 things - your milk is enough for him until he is a year old ... not just 6 months. At 6 months until a year food is still just for exploring and learning, not providing baby with the nutrients he needs to thrive. The best way to increase your supply is to remove milk from your breasts frequently, and feeding baby cereal is going to cause him to want less milk. I think your ped has given you poor advice.
The other is to nurse a ton, and if there is anyway possible to prioritize your pumping. With your LO being so young you are still establishing your supply, so the more you pump, the more you should make (Supply=demand). If you stretch pump sessions you are signaling your body to make less milk. Try not to stress out too much, you are not beyong improving your supply by any means.
Keep at it!! You are doing great. Decide what you want for your LO and stick to it... there will always be something that others think you should do different. It's your child though, and you know best!
FT working momma to a 9/11/10 busy boy and 11/13/12 happy little man.
Also wife to hubs since 8/23/08, bonus momma to H (girl) -99 and G (boy)-03