She then revealed, in a dramatic and emotional TV interview after the race, that she had spent last night in the hospital at the Athletes' Village, being sick and unable to sleep.
That followed months of injury problems for Sharp, 24, daughter of former Scotland medallist Cameron and Carol, who both represented their country at the Commonwealth Games.
Sharp also displayed her hand, on which were written the words: Get out strong. Commit.
It had looked like Sharp would miss out on the podium as late as the final bend, only to produce a wonderful surge down the home straight to beat Winnie Nanyondo to silver
Sharp's achievement is made all the more remarkable by the fact that an unspecified illness had not only put her podium hopes in jeopardy, but even the chance to compete in the final.
"This is my everything," she told BBC Sport. "This year has been obstacle after obstacle.
"Even right up to this morning I was in hospital in the village until 5:30. I haven't slept at all. I was throwing up all night. I had a drip in my arm.
"This was my everything and there was no way I was going to go through everything I have been through not to get a medal tonight.
"I know how low the low points can be and yesterday I almost blew it. I had to come out and get it right and do what I have been doing all this season."
It provoked another powerful response from the Hampden crowd, just 24 hours after poster girl Eilidh Child claimed silver for Scotland in the 400m hurdles.
Cameron Sharp, who suffered serious brain injuries in a 1991 car crash which means he has limited mobility, was at Hampden to see his daughter's run, as was mother Carol, a former 800m runner, who gave her daughter a huge hug as she completed her lap of honour.
Sharp only qualified for the final as a fastest loser, whereas England's Jessica Judd won her semi-final impressively.
The 19-year-old ran well again in the final and was on course for bronze until Sharp's move down the outside, which bumped her down to fourth.
"I gave it everything," a tearful Judd said. "It just was not to be. I'm devastated because I really wanted that medal."