How to increase milk supply

So, I haven't been able to breastfeed as much as I would like to this time around. I mainly just pump. I try to keep a well diet, drink lots of water, and pump every 2-3 hours. But, I've only been getting 4 oz if I'm lucky within that time frame.

I feel so stressed out that sometimes she wants to feed as I'm pumping that whatever I pump thats what she ends up eating and I have nothing for the next feeding in a few hours.

I've been tried lactation teas that I have 2x a day. But, honestly nothing is working. Idk what I'm doing wrong. 😥