Hi, all three of mine have been evening cluster feeders too. Does he then give you a good few hours once you go to bed?
I found that this did last a while this last one till about 4months but I put up with it because she then slept for a good 6 hours when I went to bed around 10 -10 30 at night!
Stick with it I know it is exhausting, stick your favourite telly programme on and get some snacks and go for it.
If you are getting really sore, I did 24 hours of expressing and bottle feeding which just gave enough of a break for the lansinoh to give some healing and after that was ok. Don't be afraid to do this, at 9 weeks it won't hurt your feeding.
Be good to yourself, I promise it doesn't last forever.
Boaz