Low milk supply

sat

I gave birth to my baby on September 12th. I didnt have milk initially and it started to come in by day 3. Due to some issues I havent been able to breastfeed directly but pump the milk and give my baby. I had good supply for a couple of days and was able to pump 40 ml every session. Suddenly the last 2 days there is no milk and its hard to get even 10 ml. Anyone has any ideas on this and how to address this. I am a FTM and feeling bad about it.