Leaving a no bottle baby

So my baby only nurses and has never had a bottle. We are teaching her to use a sippy cup and she can drink from an open cup with help... well I went for a work meeting today I nursed baby before her nap and after her nap. She napped 9-10:15. Then I pumped 3 oz and left her with her father. He saw me pumping but I must've forgot to tell him to give her the milk if she fusses as I was late. Got home at 1 and he said she had been fussing for a couple of minutes before I got home. I feel horrible... my poor baby was hungry and had to wait to nurse. I nursed her as soon as I got home... I'm just so stressed now... I don't know how to leave her when she only nurses but I thought he knew what to do because we've talked about it before and he was there when I pumped... bleh bad mom moment...