baby would not latch on , been pumping

Minni
Hi need some help and advise.
My girl is drinking expressed milk since she was born due to not enough weight gain, she is not interested in breasts now even though she tried hard to suck but not be able to latch on. 
Any moms here doing exclusive pumping? So far so good? I am offering her breast every time but result her so stressed and not get enough sleep( suck for hours but still need a bottle in the end) . I am very sad not be able to breast feed as it is such a bonding for me, but I think I would let it go as she gets enough milk and sleep is more than my emotional needs 
Let me know if you are exclusive pumping or your story how to transit a bottle baby back to breasts!