Learn Polish: Już nie krytykuję swoich emocji. - I don't criticize my emotions anymore.

Just like siebie means 'oneself' when the object is the same as the subject, swój (and its forms like swoich) is the possessive version meaning 'one's own'. Since the hidden subject is 'I' and I am talking about my own emotions, we use swoich. While moich wouldn't be grammatically wrong here, swoich is the much more natural choice in Polish.

What case is swoich emocji in, and why?

They are in the genitive case. Normally, the verb krytykować (to criticize) takes the accusative case for its direct object. However, because this is a negative sentence (nie krytykuję), the object changes to the genitive case. This is a strict rule in Polish known as the genitive of negation.

Why does emocji end in -i here?

It is the genitive plural form of the feminine noun emocja. Nouns ending in -cja (like emocja, policja, stacja) form their genitive plural by dropping the final -a and adding -i.

Does już mean 'already' in this sentence?

Not directly. While już by itself often means 'already', placing it before a negative word creates the set phrase już nie, which means 'not anymore' or 'no longer'.