Last place with a personal best is still a good day. The scoreboard and the stopwatch measure different things.

Two comparisons are available in any competition, and only one of them is about you. Where you placed depends entirely on who else turned up that day; what you ran depends on the months you put in. Those can move in opposite directions, and treating the first as the verdict throws away the only number that reflects your own work.

Record your own figures separately and check them against your previous ones. Improvement against yourself is the thing you actually control. Finishing behind everyone while being faster than you have ever been is a good day, whatever the results sheet suggests.