Не злись
Не сердись
Не серчай

More familiar:

Не кипятись
Остынь
Не бесись
Не психуй


P.S. I used to share apartment with one canadian.
Will always remember:
"Sergei, you left your dishes in the sink yesterday. Mr X was so mad..."
(Mr x was a landlord. Mentally he was fine.)