Wellington had hoped to be the fairytale story of the season in their first ever ALW finals series, but they were outclassed by Melbourne City 3-1 in the decider, with Holly McNamara's brace proving the difference.
Priestman conceded her players, who finished second on the table, had probably been overawed by the occasion.
"It doesn't define our season. I think that's the most important thing," she said.
"We the players, the staff, have to hold their heads high. City have been here, they've lost some finals, and you bottle this up, and you come back stronger next year.
"I've seen people be at their best when they're hungry. This leaves a little bit on us. And in many ways, it might help us next year to push to another level. I've got an ambitious club.
"I'm at my best in these moments; the hunger, the desire to push forward. I think everybody will channel that now. When we turn up in pre-season, we'll all know what could have been.
"What you learn about people in difficult moments is those who then grab it by the scruff of the neck and push forward."
Priestman conceded her players were hurting, but thought back to Canada's thumping 4-0 defeat at the hands of the Matildas at the same venue in the 2023 Women's World Cup.
"It's where you find another level in yourself," she said.
"I unfortunately had this occasion at this World Cup, but then after that you go on a 15-game unbeaten run, because you find another level in yourself, you ask yourself hard questions, and you push again.
"And I think these are the moments that make players, make clubs, depending on how you respond. And I think how you respond in life is the biggest thing.
"I've got no doubt that dressing room will respond in the right way and push on, and we're moving forward."
Priestman said the Phoenix's season, her first football job after serving a one-year suspension over Canada's Paris Olympics spying scandal, had been one of her most enjoyable.
Wellington have 12 players on contract and will regain Samba (ACL) and CJ Bott (pregnancy) next season.
"The players coming back, it's nice to know that they can bottle this up, and then you inject a little bit of energy or maybe some added quality into the group," Priestman said.
"I will do everything in my power to make sure we are back here next year, and we come back, and this grand final is no longer new to this group, and we can cope with that occasion, and hopefully give a better account of ourselves."