Advice

So I been doing Cross Country for about 6 years now and I don’t know how but these new comers are faster than me who just started last year so I don’t know what else I need to do to get better they run a 19:00 19:10 and I ran a 21:15 which is pretty bad but I don’t understand how I haven’t improved as much as they have should I just keep on working harder and keep on pushing myself or just deal with it cause today even the newer people did too but they were in the 20’s and up