Does she eat expressed milk? If I needed to go somewhere alone, I would leave breast milk for her. If you feel two stressed about leaving to someone - why don't you nap when baby naps? Do you go for long walks? My baby was used to going out for 2-3 hours in pram, so when I needed time for something I could use that time and somebody else could walk outside with her. Moms naturally feel quietly and anxious when separating from babies, but if it gets too overwhelming for you, you need to find a way to get the rest needed before you get too insane. I know what I'm talking about - I've gone insane with two little kids (my second was born when first one was less than 2). It's still hard for me to acknowledge my needs, my borders because babies needs naturally come first and moms are ready to scarifies everything. But the thing is - babies are happy when their moms are happy.
Other thing for night feeding - do you sleep with your baby in the same bed? For me it was lot easier if we slept together and I didn't have to bother waking up fully and not falling asleep while feeding. Safety of course needs to be considered.