Sorry that you are struggling with milk supply. I have a 4 month old and just pumping barely enough for him to continue exclusively on breastmilk. I find that Hong Kong does not have any organizations or programs for breast milk banks for donations or sharing. The only recommendations I have for you are some things to increase your milk supply:
1) rest - sleep is essential to you being able to produce milk. I know it's hard but you must get as much rest as possible
2) hydration - drink lots of water or coconut water throughout the day
3) foods that can help increase supply: papaya, pumpkin (and pumpkin seeds), moringa leaf (can be found at the Philippine grocery store in Central), nuts (like almonds, cashews, chestnut), green leafy vegetables.
The first few months are hard but please don't give up - hope this helps!