What does J'AI LES GLANDS mean in English?

"J'ai les glandes" is a familiar expression, borduring to slang, meaning something along the lines of "I hate that, I'm upset" in French.

"Avoir les glandes" has for second meaning being afraid (in that case, people prefer using it to talk about someone else). You can also say "J'ai les boules".

In those two expressions, "boules" and "glandes" are used as synonyms for testicles (close to nuts).