Ugh, ((((hugs)))) and get well soon vibes.
I've been there, done that
Just before Christmas, I ended up with a bug. I was WIPED by day 3 of no food staying in my system and feeding Little Man. Drinks such as dioralyte (sp?? Hydrating salts and electrolytes) and even flat 7up heated in the microwave helped when my body could manage it. Also, when my body could take it on day 3, I had wheetBix with lots of hot milk so it was almost like soup and that helped to bring me back. I felt like I was going to pass out after 3 days running below empty and feeding throughout.
My supply wasn't affected - it seemed like Little Man got ALL he needed & I was the one left deficient.
Hoping you're feeling back to yourself really soon.