try doing skin to skin it works on me even at 14 months into bfing. my supply drop and I got it back by doing lots of skin to skin. you can dm me at my Instagram @mummyJlife I can give you some advice from there if you need help
you can consult a lactation consultant or seek advice from the 'breastfeeding mothers' support group singapore' - they have a number to call or a whatsapp group
https://sg.theasianparent.com/how-to-increase-breast-milk-supply