Did anyone else here have a low supply?

My daughter is 15 months, I'm still nursing her, but I have a low supply. Like seriously, right now, all she's really using the nursing for is comfort as she gets a negligible about of milk. I was diagnosed with a low supply when she was 3 and a half months old and had gone beyond slow weight gain to actual weight loss. I was fortunate enough to be a recipient of donor breast milk, so I didn't have to use formula with her until she was about 10 months old and donations slowed down at the same time as I was taking a vacation.

Now that she's over a year old, she gets cow's milk with meals and nurses when she wakes up, before and after naps, before bed, and the one or two times she wakes up overnight. When they doctors told me I didn't make enough milk, I wouldn't have believed I would make it a year past then, but I managed it, and it doesn't seem like we're going to stop any time soon.

Has anyone else had that same struggle?