Help: Exclusively Pumping, increasing supply

I encountered about every possible difficulty with breastfeeding so I've been pumping since week 2 and supplementing with formula when I run out of expressed milk.  Baby is now 6 weeks old, but I still don't have enough milk to completely feed him. I pump about 7 times a day: 5- 20 minute sessions and 2 longer power pumping sessions. I take supplements, teas, etc. I get a bit under 3oz (90ml) per session from both breasts.

I'm starting to get a bit discouraged and have to make a decision moving forward of whether to continue or not. Does anyone have any advice? Is 6 weeks too late to establish a full supply? Should I be pumping more often?

P.s. I'm waiting to receive pumpin pals to see if it helps because I have elastic nipples.