I think you may be attaching your feelings to your dog. How do you know she is uncomfortable backpacking? I can see how she may not like riding in a car. Our border collie loves riding in the car, but does "seem" anxious on the trail with ears slapped back. A herding dog's job is to protect their "flock", which is us, and away from their familiar territory (home) it is normal for them to be more anxious. Nevertheless, our dog also shows a lot of pleasure. I walk her daily at home, and often go on different routes so she gets more comfortable with the unfamiliar.
As for sleeping with you, it may be too late to start that, but we put our dog's sleeping pad in her crate at home when she was a puppy and then put it in the tent, and she just naturally preferred to sleep in the tent on the pad. Although she sleeps with us in the tent, at least once a night she barks at stuff. Since we are old farts who have to pee at night, she goes out with us and seems to be satisfied with that amount of out-of-tent time.