Elise Christie's Sochi 2014 ended in dismay as she was penalised for a third time in one Games during her 1,000m short track speed skating event.
The Briton was judged to have impeded China's Jianrou Li on the final lap of the semi-final as they both fell over.
"Never in 100 years did I expect a penalty. I'm confused and heartbroken," the 23-year-old told BBC Sport.
"I knew you needed a lot [of mental strength], but I didn't know it would need this much."
Christie, the reigning European champion and a world bronze-medallist over 1,000m, was looking to end her Sochi campaign on a high after being disqualified in the 500m final, judged to have not finished her 1500m heat and receiving abuse on Twitter.
The 1,000m had been seen as Christie's best medal chance pre-Games, and the 23-year-old comfortably negotiated her quarter-final.
She began the next race cautiously, but then tangled with Jianrou as they jostled for positions before spinning off on the last corner. The Briton skated gingerly over the line in last place.
Great Britain's short track speed skating performance director Stuart Horsepool was shocked by the judgement.
"I had a small look at it [the semi-final] - we have to respect the decision of the referees," he told BBC Sport. "But I think it's outrageous and I'm heartbroken.
"We have put together a great short track team and ultimately we came here with medal opportunities, wanting to fight on Friday.
"I am disappointed, frustrated and quite angry at the decision of the referee. You have to respect the decision of the referee but he was wrong."
BBC commentator Wilf O'Reilly, a former Olympic short track skater, initially thought Christie was not at fault and would be promoted to the final.
But, after seeing the incident again, said: "Elise Christie was protecting her position before the collision happened. That might be why she has been penalised.
"She was not at fault for the fall, but it may because of the earlier incident. Even so, it would be extremely harsh."
Had Christie won a medal on Friday, Britain would have completed their best-ever Winter Olympics.
Team GB currently have four medals - curling silver and bronze, skeleton gold and snowboard bronze - but have never in history won five medals in one Winter Games.
"I was finding it really tough and trying to hold myself together for Great Britain," added Christie, who won world bronze over 1,000m in 2013.
"I really wanted to bounce back [from earlier Sochi failures] and was so pumped to do it for everyone and for myself. To have the chance taken away - whether I had won a medal or not - is devastating.
"I have been so proud of watching the other team GB guys compete and wanted them to be proud of me.
"I will come back in four years and try again though - you can be sure of that."
Meanwhile, Jon Eley, the three-time Olympian who was Britain's flagbearer at the opening ceremony, was eliminated at the semi-final stage of the men's 500m.
He subsequently came third in the B final to finish seventh overall.
"I'm very disappointed not to get to the final but I am pretty pleased with the way I have turned my season around. At Christmas I was struggling and didn't think times like this would come again.
"The past couple of days I have been skating better than I have ever skated before. I was feeling up for it, I skated beautifully in the quarter-final and it was just a slip in the semi-final cost me."