I’m stubborn and I love machine quilting so I do queen size quilts on my domestic. I agree with the suggestion to watch some videos. One thing I do is loosely accordion fold the part of the quilt that goes on the right under the harp. It makes the quilt less bulky but much more flexible than if you rolled it up.
You only need the area of the quilt that is near your needle to be smooth and flat.
i hope you don’t give up. There’s a great feeling of satisfaction when you’re finished.