Pumping/Nursing schedule

So I’ve been supplementing... and my supply has plummeted. I wanted to get it back up but I’m not sure how? I have mothers milk tea. Is there a good time to drink it? I also read in my What to expect book that I could breast feed her and then feed her formula after my breasts are empty to see how much she is getting from me, and it says to pump 5–10 minutes after I’ve fed her. Should I do that right after I’m done nursing her or can I wait until she’s done with the bottle? HELP!