The Coasters were bidding for promotion to the EFL but lost out to Salford City, eventually losing 3-0.
But Challinor, whose side finished fifth this season insists they have to continue improving.
"You can always look back and think ‘what if’ but ultimately today we’ve not been good enough," he said.
"But that can go two ways, you can either kick yourself about it and feel sorry for yourselves, or you can use it as motivation, which we have to do.
"It’s disappointing and difficult but I won’t be feeling sorry for myself. There’s always going to be bumps in the road and today was one of them.
"But the league’s getting tougher every year and you can’t stand still," he added. "We’ve improved this year and our aim next year will be to improve again. You’ve got to use disappointment as a learning experience and go again."