Perhaps you could do more than one project at a time if you thought of the projects as having different purposes. You could have a quilt that you worked on in your sewing room. You could have a quilting project - perhaps hand sewing some blocks or hand quilting a quilt-as-you-go block-that was strickly done when you were waiting in a doctor's office and/or riding in a car, sitting/visiting in the hospital, etc. Or think of one project as at home and one as away from home. Later you could try two projects at home.
I think you could do 2 or more projects at a time if you can mentally compartmentalize them differently.