Iga Swiatek described the inner turmoil and "chaos" of her doping ban on Friday ahead of the Australian Open, calling it "the worst time in my life".
Swiatek pulled out of the WTA's late-season Asian swing in September citing "personal matters".
Only later was it revealed Swiatek had been absent because of a one-month ban for testing positive for a banned heart drug.
She denies knowingly doping, saying it came from contaminated non-prescription medication.
"Trust me, I was the one that was the most surprised," the Polish world No 2 told reporters in Melbourne.
"I had no idea what's going to happen. The first three weeks, I would say, were pretty chaotic. I had no idea if my suspension was going to be lifted soon or not.
"It was probably the worst time in my life.
"And the fact that I had no control over this whole situation and I had no chance to avoid it made it even worse because I'm a control freak a little bit."
Swiatek returned to the circuit with four straight singles wins in the United Cup until coming up against Coco Gauff in the final, where she went down 6-4, 6-4.
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"I think it was great preparation before the first Slam," she said.
"I think the quality of my game was also really nice. It also gave me some confidence."
Second seed Swiatek begins her Australian Open campaign against Czech doubles specialist Katerina Siniakova, ranked 46.
The Polish star has fourth seed Jasmine Paolini, sixth seed Elena Rybakina and eighth seed Emma Navarro lurking in her half of the draw.
But the five-time major champion cannot face the world No 1 and defending champion Aryna Sabalenka until the final, should she get that far.
The 23-year-old Swiatek has never shone at Melbourne Park.
She has only progressed beyond the fourth round once, in 2022, when she was upset by Danielle Collins in the semifinals.