Have you done any over distance stuff? 800m or less repeats with good recovery?
Are you getting good gym work in (Squats, Cleans, RDL, etc.?) Core work as well.
Did you run indoors or only running outdoors?
Basic week includes 200m repeats one day, over distance another day (anything over 400 and max 800) and speed endurance day 300s/45 second efforts later in the season. Lower body focused gym 2-3 times and upper body 1-2 times depending. I used to alternate MWF lower body T/TH upper body.
Rest on weekends and/or compete.
From your PRs I'd say you need to get a little more speed or definitely work on efficiency to break 50. I first broke it running around 23.0 and 11.4.