When it comes to expressing that you are focusing on or engaged in something, there are numerous synonyms for the phrase "occupied with." If you are busy with a task or preoccupied with a thought, you can use terms like engrossed, absorbed, immersed, or fixated. If you are working on a project or studying intensively, you might say you are concentrating, devoted, dedicated, attached, or committed. If you are caring for someone or something, you can use the terms responsible, concerned, or attentive. There are plenty of other ways to describe being occupied with something, so choose a word that best fits the context and conveys your intended meaning.