"A lonely young man gets caught up in the craziness of an exclusive nightclub that he discovers might be trafficking drugs but he soon falls head over heels for a quirky girl who is addicted to the club, the only way to save her and maybe himself is to bring it all down."
What it boils down to is a love story with a drug addict (regardless of what the drug is) and his efforts to save her from killing herself. Try to simplify it without too many of the extraneous details.
The problem is less about the logline than the concept itself. I don't see a "hook" and therefore, it doesn't differentiate itself in any way. My suggestion is to create a hook for your story the highlight that in your logline.
Good luck! (Geno Scala- judge)