FTM and low supply- recommendations to increase supply?

Hello, I'm a FTM and my baby is 12 days old. I was in hospital after birth for 7 days and was late to pumping/breastfeeding.
Now it feels like I'm trying to catch up and get my milk supply up. I've tried lactation cookies, mother's milk tea & pumping every 2-3 hours but nothing seems to be consistently working. I’m also having some nipple sensitivity, using nipple butter but still wince when I increase the vacuum on my spectra. I have to start in lowest let down mode and work my way up, then transition to pumping mode and work my way up there.

I'm getting 15-30ml on one side and max 20-30ml on the other side most pumps. I started simulating cluster feeding by doing 20 min on, rest 10 min, 10 min on, rest 10 min and then 10 min one which resulted in 60ml and 90ml
today (2nd day trying this & got more today than yesterday) but then goes back down after that for every other pump.

Any recommendations on something that will consistently increase my supply and how long it takes before the nipple sensibly goes away. Thanks!