What is it that I'm interested in, Astronomy, Astrophysics, Cosmology, physics?

Easy, Physics. Which is a general grasp on all of your aforementioned interests. However, physics branches off into the study of the small "quantum physics" and the study of the large "astrophysics". You mention interests in both areas so a general physics degree sounds most suitable. You can then engage in more specific areas of interest once you reach graduate level studies.