Leaving baby for the first time over night.

First weekend in August I'm leaving for a trip for 3 nights. I had a ton of breast milk but it all defrosted and is no longer. So now I have 3 weeks to pump enough for her. I'll be leaving a Thur and coming back Sunday. Ant advice to get enough milk and how much to be safe should I try and pump? I am beyond nervous about leaving her she hates bottles and is 100% a momma's girl and has never been away from me longer than a few hrs. She will be 9 months when the time comes. I'm scared I'll be worried about her and not have a good time I couldn't sleep last night thinking about it. Ugh