breastfeeding help!

Britt • 👦🏼💙 May 27, 2016 ;👼🏼 12weeks Nov 2017 ; 🌈 💙🧒🏼March 8, 2020 💖👶🏻 Aug 3, 2021
My LO is almost 4 months and lately when I feed him at night (it seems to mostly be in the evening) my letdown is crazy fast that he has started biting me. He doesn't have teeth yet but my gosh it hurts and I'm worried when he does i'm going to have to stop immediately. I've tried to express some out (it squirts from multiple spots) but he still gets irritated and what used to be a 15minute feeding is now 45 because it takes him so long to settle. 
Has this happened to anyone before? Is there anything I can do? And also is it weird that this hasn't really been a problem until recently?