I said FORMULA ONLY then she was born

They put her on my chest and she went right for my boob and i didn't say no, now 2 Days pp and I'm still trying it is very painful 
My nipples are very sore 
Is this normal ?? 
They said baby has good latch but has a strong grip 
Need advice 
Can I use numbing cream or what can I do
It dosent hurt as much on the left breast but the right one oh my gosh 
Is if bad to just have her feed from mostly that one?