It's likely you're missing a word or two to complete the phrase and convey a specific meaning.
Here are some possibilities depending on the context:
Possible completions and meanings:
* Je suis sous l'effet de... (I am under the effect of...) This phrase refers to being influenced by something, such as drugs, alcohol, or a strong emotion.
* Je suis sous la pluie. (I am in the rain.) This indicates being physically outside and getting wet.
* Je suis sous pression. (I am under pressure.) This implies being stressed or burdened by responsibilities.
* Je suis sous contrôle. (I am under control.) This means being in charge of a situation and managing it well.
Please provide more context or the full sentence so I can give you a more accurate translation.