I'm no help at all Karina, my baby girl is 8 months old & I'm still funny about leaving her for an hour or so with my own Mum!!! My Mum has had 4 children & is 200% capable of looking after babies, but I'm just not ready yet.
As for breastfeeding, try to get her used to having EBM every now & then, just to make sure she'll take to the teat. I hope it goes well for you, it'd be great to get out & have a bit of a break!