Help??

So I had my baby Thursday and last night I noticed my left breast is hard and it's hard for baby to latch onto. I tried to squeeze some colostrum out but nothing would come so I used my pump and got 1 oz out , I stopped because I didn't want to much out. But it's really hard and kinda sore. How do I fix this? My right one is starting to do it too but it's much better after baby eats .