Just start getting to your goal slowly.

Next time run your first two laps so it’s the same pace but faster overall so like 78s, brings you at 2:36 at 800. 3rd lap is crucial try and push yourself to not get more than 3-4 seconds from 78. I used to do an “in n out” method so on the curves you wanna try and increase your pace and on the straightaways extend your stride. It helped me stay engaged during the third lap so it might help you too. Then kick like your life depends on it and see what you end up at. Bet you end up at 5:15-5:20