How do I make more milk??

There is a lot going on I’m my life right now but the short version is. My daughter is one month old and has only had formula. Im having to pump and dump until my doctor says it’s okay to start breastfeeding her. For the first week or two I was producing like 2oz or 3oz every three hours. Now the most Im getting is 20ml maybe 40ml if I’m lucky. Im scared i won’t be able to produce milk by the time I’m able to breastfeed and it’s making me super depressed. I’ve been crying almost every time I pump because it’s so little. What am I doing wrong? How can I produce more milk? Is it my diet? Because I’ve been producing so little I’ve been pumping less but even if I pump every two hours all day nothing changes. Someone please give me some advice