I then told iTunes to consolidate files which it di by copying all the files over to the new location. I then deleted the iTunes folder on the C: drive (SSD),
Although you've shifted your media/content files over to the other drive, you haven't shifted your iTunes library files (containing the database which tells iTunes where all your content is). So when you delete the entire iTunes folder, you're deleting your iTunes database, and iTunes opens empty.
Instead of deleting the entire iTunes folder, try first dragging the iTunes media folder (inside the iTunes folder) out onto you desktop. Now try opening iTunes. Is everything still there and playing correctly and so forth? If so, it should then be safe to delete the iTunes Media folder on the desktop.