Could there be a connection between sugar addiction and yeast?

Yes: Yeast grow by fermenting sugar ― so your sweet tooth actually feeds them. In addition, having treated thousands of patients with candida/yeast overgrowth, it seems clear that the candida also triggers sugar craving so that the yeast can get fed. Unlike type 2 sugar addiction where people get irritable when hungry, sugar cravings from yeast do not make the person irritable.