Swimming sensation Rikako Ikee said Wednesday her battle against leukemia has been more difficult than she imagined.

Three weeks after announcing she had been diagnosed with the disease, the 18-year-old, who holds multiple national records, shared her feelings with her more than 400,000 followers on Twitter.

"It's tens of times, several hundred times, several thousand times harder than I thought," she wrote.

"I haven't eaten in more than three days. But I don't want to lose."

Ikee's announcement last month sent shock waves across the country, as she was considered a medal hopeful for the 2020 Tokyo Olympics. Words of encouragement and support have poured in for the teenager from around the country and the world.

Ikee revealed that she received the diagnosis after cutting short her training camp in Australia. She has put all swimming-related activities on hold in order to focus on her treatment.

She will skip April's national championships, which serve as a qualifier for the world championships.

Ikee had a breakout performance at the Asian Games in Jakarta, where she was named MVP after becoming the first swimmer to win six gold medals.

She holds national records over 50, 100 and 200 meters in freestyle, as well as 50 and 100 in butterfly.