Child forgot how to breastfeed?

My baby (10 weeks) woke up the other day and suddenly doesnt know how to latch anymore. He doesnt get a complete feed now, full of wind & cries because he is hungry. Not to mention my boobs are killing me!

I express now quite a bit now and I just want to know whats happened, he took so well and now cant seem to get the hang of it no matter how I hold him. Partner & mother dont see a problem with him taking the bottle of expressed milk fine but I want to know whats happened.

Anybody know? An idea? Anything will help

P.S. he is very cute