Breast feeding

My boy just turned 1 month yesterday and I'm struggling with my milk supply. In the morning I can pump 2 oz from one breast and I let him eat off the other. Through out the day I rotate and have him eat off one and pump on the other... I do this every 3-4 hours.  I find that I can only pump 10-15 ml per 15 minutes throughout the day.... I'm taking fenugreek 3 times a day and also a tea spoon of Brewers yeast (stuff is nasty). I drink about 28 ozs 3-4 times a day of water. I don't get why I can't get more milk. Any advice is appreciated. I went to a lactation consultant and she told me not to supplement and I did this for 2 days but by the end of day 2 he was extremely fussy. I supplement about 2 bottles a day and it's usually at night when he's fussy😞. He gets 3 bottles a day and the third is usually 3-4 oz of the breast milk I got throughout the day.