Milk supply drop - help!

Baby is 15 weeks and is exclusively breastfed. The past couple days baby won’t feed properly, literally comes off the breast after a few minutes.

So I pumped.. and I’m getting like less than half of what I usually got a few weeks ago. I’ve gone from getting about 110ml to 50ml..both breasts after 20 mins pumping.

So I’m assuming that’s why baby won’t stay on.. there’s not enough milk anymore.

Has this happened to anyone? Does this bring my breastfeeding journey to an end?