other + plural nouns (other people, other women)
another + singular noun (another person, another woman), you cannot say anothers, it's incorrect
the other: when you talk about one of two things (I don't need this pullover, I'll take the other one.)
the others: when you talk about a group of something/somebody (Where are the others (=the other people)?), you can only use it when the reader/listener already knows what you mean.
otherwise is a conjunction, meaning "or else" (Tell me the truth otherwise I'll leave you right now.)