Pain!

Dj
My son is 5 weeks old and for some reason he latches really well on my right side but not on the left? I've been having so much pain trying to feed him from my left side, my nipple cracked and I got a small blister. 
I've been just trying to pump from my left side and nurse from my right but this evening when he was cluster feeding he drained my right side and when I tried nursing from the left I was in tears from the pain. He would fall asleep and then wake up 5 minutes later like he was starving so hubby fed him 3oz from a bottle and he fell right to sleep so I know he wasn't getting enough from me.
My question is what can I do to help the pain and get him to latch better on the left side ?