Supply dropping?

My LO is currently 3.5 months old. In the beginning I had an over supply and I have a deep freezer with a ton of milk which I’m grateful for. However the last two days my baby has been fussy at the breast and I’ve noticed she has to suck for a bit to get a let down. Where before I think I had so much milk I didn’t event notice a letdown during a feeding.

But she’ll unlatch and start crying and it takes awhile to get her drinking now. I thought maybe she was teething but I really think it’s my supply as my breasts don’t feel full like they did.

I’m not taking any new medications. I’m drinking a lot of water, but my sleep still isn’t great.