Je me sentais énervé.

Énervé = irritated

In Quebec, it can apparently mean “excited”.

Enervé refers to “nerves”, so you can see how the two meanings you gave are compatible.
“to get on one’s nerves” might help to remember the meaning of irritation

But the translation given is “I felt excited”, which is a positive feeling, whereas “énervé” gives me a bad feeling.