Help with plastic taste in water cooler.?

i bought one of those water coolers that you put the big jug of water in top of and then it cools it (like the water things that they have in businesses) well anyways it had this awful plastic taste in the water so i filled it with water and viniger. i forgot that it had stuff in it and so when i remembered 3 months later i went to drain it and there was mold in the water and viniger. what can i clean it with that will get out the mold? and what else can i try and get the plastic taste out with? is the mold dangerous to drink if there is still some in it. PLEASE HELP!!!