Learn Swedish: Jag är väldigt berusad.

Berusad translates more closely to intoxicated or inebriated. It is slightly more formal, polite, or clinical than full. You might hear berusad in a news report or use it if you want to sound a bit more delicate about your state, whereas full is the standard, colloquial word used among friends.

What is the difference between using väldigt and mycket in a sentence like this?

Both mean very, and jag är mycket berusad is perfectly correct. However, at a B2 level, you will notice Swedes often prefer väldigt to intensify adjectives in everyday speech. It originates from the word for enormous or huge (väldig) and tends to sound a bit more expressive and natural than the neutral mycket.

Is berusad an adjective or a verb?

It functions as an adjective here, but grammatically it is the past participle of the verb att berusa (to intoxicate). It is built from the noun ett rus, meaning an intoxication or a rush. Because it acts as an adjective, remember that it must agree with the subject: if the subject were plural, it would become vi är väldigt berusade.