Oh man how do I quit T__T you let yourself drink once and all sudden it's an everyday thing.
aspartame, aculfesame, and sucralose have all been cleared through rigorous studies (100+) that identify zero carcinogenicity and otherwise negative health effects when used within recommended daily values. Energy drinks do not exceed these values when drank once or twice a day. I would hazard the greatest concern regarding kidney/liver associated with energy drink abuse (4+ drinks a day).