Please help! Supply changes daily: Feast or Famine?!

StacyJYay

I'm a lurker who has learned so much from you all!  I'm coming out of lurkdon because I'm facing a problem that I haven't seen on the board yet.  My son (4.5 months old) is EBF, but it has been a struggle, and we're currently facing a "feast or famine" situation...  

In order to lactate, I've been on Domperidone (160 mg/day) since he was 1 month old.  At 3 months, when I tried a lower dosage of Domperidone, my milk literally dried up to nothing.  I immediately increased the dosage and spent 2 weeks furiously pumping and continually putting LO on the breast, and I managed to "relactate." 

The situation I'm facing now is that my milk supply varies day-by-day.  For, let's say, 5 or so days, my milk will be abundant (enough to feed my son and stash 10 oz from pumping), and then -- BOOM! -- out of nowhere, for the next few days, my supply will be so low that my LO will get maybe 1-2 oz at the breast per feeding.  (We have an infant scale at home, so we can do weighed feedings.)  During these low supply days, my LO is terribly unhappy (understandably) and has far fewer wet diapers, so I know it's not okay. 

Has this happened to anyone?  What could be causing this? I feel like my poor LO faces a "feast or famine" situation, depending on the day... 

Thanks in advance for any help!!!