Anybody somewhat exclusively pumping? Help!

If so I have some questions.

How much do you get out of each side at each pump?

How often do you pump?

Have you tried mother’s tea or fenugreek or any postnatal lactation vitamins? If so what did you do and what were your results?

Also, how many ounces is your three week old taking and how often?

We’ve tried latching and he does okay sometimes but sometimes he gets totally flustered and can’t and shakes his head pretty violently. So we bottle feed breast milk. I was pumping 12+ oz each pumping session but literally now I’m down to maybe 4oz total.

All any every opinion/ experience are welcome, because I’m desperate to keep pumping until at least a year 😥