It's a nursing strike, quite often caused by teething. They associate feeding with pain.
At this age they can last around 1-2 weeks, which is emotionally exhausting, as everyday can feel like forever.
You can take him to the doctor to rule out anything, like ear infections.
Most people find that feeds either when they're drowsy (just woken up) or still asleep work first.
Key is just casually offer, but don't force the issue as that will create more problems
You can also search nursing strikes, there has been a 10 monthers lately. I reckon someone tomorrow will probably come along with a link.
This doesn't have to be the end if you don't want, but be prepared for a tough ride. It's hard but try not to take it as personal rejection, because it is no reflection what you whatsoever.
If you're worried about supply, then pump. Your supply will most likely dip anyway, but trust that when he started feeding again it will sort itself out.
Also if you want feed more than twice a day, then do so :)
good luck