So we use "really" in English to stress the importance of something. "I really need to go". "I really could use a drink". "I am really tired".

What word do I say in Russian to be the equivalent of "really" in these scenarios? There are so many to choose from:

adverb
действительно
на самом деле
уж
в самом деле
впрямь
разве

interjection
право
разве
вот как
не может быть
вы так думаете



So which one do I choose?