Her time in Japan has been tough but Australia's Emily Seebohm believes the Tokyo 2020 Olympics will be a "breeze" compared to her Pan Pacs experience.
An emotional week appeared to catch up with Seebohm when the world champion was relegated to a shock sixth placing in the 200m backstroke final on the last night of the four-day Pan Pacs in Tokyo on Sunday.
She bounced back to feature in the 4x100m medley relay team's stirring win in a new championship record, taking her personal Pan Pacs tally to two gold and one silver.
Seebohm admitted she had been struggling as she came to terms with a very public break-up with teammate Mitch Larkin that almost forced her to pull out of the year's major swimming meet.
But in the end, Seebohm was glad she didn't.
The 11-year team veteran said she was more motivated than ever to tackle Tokyo 2020 thanks to the strength drawn from her Pan Pacs campaign.
"It's been a different battle to deal with every day [but] I pulled through and I swam and I swam better than what I thought — I am extremely proud," she said.
"So if I can do this, then I feel like 2020 will be a breeze."
The world 200m backstroke champion was in and out of the Dolphins camp in the lead-up to the Pan Pacs due to the break-up and at one stage contemplated not returning.
Seebohm did not show any signs of rust at first, featuring in Australia's 4x100m freestyle gold medal-winning team and being pipped for 100m backstroke gold by world champion Kylie Masse of Canada by 0.11 of a second.
However, the 26-year-old admitted she finally felt the pinch in the 200m final on Sunday that was won by American Kathleen Baker in a championship record of 2:06.14 seconds — almost half a second slower than Seebohm's 2017 world titles 200m winning time.
"I just knew that my 200m was going to be the harder one because I have missed a lot of aerobic work that I normally do," Seebohm said.
"So I knew that was going to be tough but I'm really happy with where I'm sitting considering the prep that I've had.
"It's pretty much a confidence boost leading into next year knowing that if I did that off what I did, then next time around it should be a lot better."
Seebohm said she would not be short of motivation ahead of 2020 thanks to the presence of Pan Pacs female swimmer of the meet Masse and American world record holder Baker.
"I think that just makes us work so much harder when we go up against each other because we're all so even," she said.
Seebohm helped Australia earn a Pan Pacs tally of eight gold, 12 silver and seven bronze, well behind world number one, the United States, which had 18 gold, 13 silver and 12 bronze.
US swimmers on notice: Campbell
Despite the results, Cate Campbell is adamant Australia have struck a major blow to the US's confidence at the Pan Pacs ahead of Tokyo 2020.
Campbell on Sunday grabbed her fifth gold medal of the meet by anchoring the 4x100m medley relay team's victory, ensuring Australia's women swept all three relays in Tokyo.
Campbell reeled in American Simone Manuel in the final leg as Australia — also featuring Seebohm, Emma McKeon and Jessica Hansen — clocked a championship record three minutes, 52.74 seconds.
Campbell began the night with gold number four, dominating the 50m freestyle also in a championship record (23.81 seconds) to fall 0.14 short of the world mark while McKeon claimed bronze.
Ex-world champion Campbell believed the all-conquering Americans were now looking over their shoulders ahead of Tokyo 2020.
"I would say we have definitely put them on notice," she said.
"They came into this with their chests all puffed out, and we have kind of taken a little wind out of their sails which has been really nice.
"There are a few less choruses of 'USA' every time they walk past which is always really nice."
But Australian head coach Jacco Verhaeren was wary of results at a Pan Pacs meet that doubled as the Americans' 2019 world titles trials.
"I am definitely not here to comment on the USA results because I do think they are a competition within a competition," he said.
"No doubt that has had a big impact on their team dynamics. Where they used to come together as a team they are now racing each other for a spot on the world championships team."
However, Verhaeren believed Australia were "on the right track" thanks to standout performances by Campbell, Olympic champion Kyle Chalmers, rising star Ariarne Titmus and their women's relay teams in Tokyo.