is anyone else mixing up 機会 with literally everything else

so i keep writing 機会 when i want to talk about my computer or machines but my teacher said no thats opportunity??? but they literally sound the same kikai and kikai!! also a tip for pronuncation you gotta emphasize the KI like you are unlocking a door with a key key-kah-yeee if you say it like key-eye people think you are talking about weird stuff anyway i just use 最大 to mean big opportunity but apparently thats wron