Pumping help?! No let down?

I’m a new mom and extremely new/naive to pumping. I have exclusively pumped since I gave birth to my son. I have a Medela Lactina Electric Plus through the state WIC program. I’ve been using it for about 3 days now. I have only ever been able to pump 3 to 4 ounces total, 4 ounces on a good day. One pump session for me was 40+ minutes with my old Evenflo pump, now 20 to 30 minutes with the Medela. I try to pump every 2 to 4 hours. I have tried lactation shakes, oatmeal, mother’s milk tea and power pumping. I have also tried fenugreek supplements which my son had a reaction to. He is 7 weeks old and is eating 5oz every 3 to 4 hours. I have to supplement with formula because I can’t keep up with the demand. I also believe I’m not having a let down, I don’t have the “tingling sensation”, or any other sign of a let down that I’ve heard about. My milk comes out drop by drop. I would greatly appreciate any advice! I’m beyond desperate.

This photo below is from when I used the Evenflo pump, this is the most I have ever produced.