Foxy, I'm so sorry your visit to clinic wasn't better. You are such a wonderful and devoted mother with very lovely (and well behaved ) children, please don't feel like a failure.
If you're interested, the homeopathic remedies to support breastmilk/bf are urtica urens (30c potency) - take 3 times a day at feeds when you feel your are at your lowest. If that doesn't work, lac defloratum, 30c potency and same as above. You can get urtica at Neal's Yard.
JBM, personally i wouldn't wake baby sleeping through the night. if you are worried, can you dream feed before you go to bed?