Messed-up is an informal term that is used to describe a situation or a person's state that is chaotic or disorganized. If you need to find an alternative to this term, there are plenty of synonyms that you can use. For instance, you can say that something is disordered, jumbled, scrambled, confused, haphazard, muddled, chaotic, or cluttered. Alternatively, you can describe someone as being troubled, distressed, unnerved, discombobulated, or flustered. These synonyms convey the same meaning as messed-up and can be used in different contexts or situations to describe similar situations or people.