I'm frustrated/ stressed with work after 10 years / never got promoted .

I got highest score on excellence for yearly evaluation.no one ever complains about me. Checked every month for promotion job coming up but never see any . But these two weeks two of the coworker under me got promoted . They barely worked there and always ask me for advice on work . They don't know much but got hired for job. I would usually help them out . now they r above me. Something going on cuz I seek know promotion listed. I'm email letter to supervisor . Help! What should I write in letter - what I should say. Thank you .also I'm a man Scorpio ox sign . Will this year better in career or promotion .or I should find new job.