Oversupply / over active letdown

Does anyone have this? I go to a mommy group and I mentioned my EBF 7week old has green or yellow frothy poo. I knew I had an overactive letdown but the lactation consultant believes my over supply is causing this along with her gassiness. She gave me some pointers, but I feel like nothing is working to get her my hind milk. Any suggestions or sharing experiences are welcome for some encouragement.