A student has spoken of the impact that the A-level results chaos during the pandemic has had on her mental health.
Rosanna Baharie said grades awarded by her teachers in August 2020 were below what she could have achieved in exams.
The 19-year-old, from Crowborough, East Sussex, missed out on her dream university placement, and was left feeling anxious and depressed.
The Department for Education said it trusts teachers to use professional judgement to determine grades.
Ms Baharie had been predicted AAA and hoped to go University College London or King's College London.
After exams were cancelled, she was awarded grades of BBC based on teachers' estimates, and eventually secured a place to study biochemistry at Queen Mary University Of London.
She said the experience left her feeling "really depressed" and affected her new life at university.
"It [was] really hard to go through freshers' week and try and make friends when I was crying every night because I wasn't in the place I wanted to be," she said.
A-level results were changed four days after being announced following an uproar over the use of an algorithm that had downgraded about 40% of results.
Ms Baharie watched her friends celebrate as their grades soared to those estimated by teachers.
But she disputed the grades awarded by her school, and said that the lack of an appeal process has had a lasting impact.
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On 10 August, A-level students will receive grades decided by teachers after exams were cancelled for a second year due to the pandemic.
Dennis Sherwood, a former consultant with exams watchdog Ofqual, said the reliance on teacher-estimated grades had been "really disadvantaging students", adding that they "can't appeal against teachers' judgements".
"The denial of access to a second opinion is really a denial of access to justice," he said.
Ofqual said that students had not been able challenge a school's academic judgement because "in the circumstances of last summer, no one was better placed than a student's teachers to judge what their likely grade would have been if exams had taken place".
Students were told to speak directly to schools if they felt grades did not "honestly and fairly" represent what they would have achieved in exams, it said.
This summer, a modified grading system has been used, and students will be given broader scope to appeal, Ofqual added.
Ms Baharie's school, the Beacon Academy in Crowborough, said it was not able to comment.
A Department for Education spokesperson said "every effort is being made to ensure pupils are able to move on to the next exciting chapter of their lives".
It said it had worked with Ofqual and the education sector to "put fairness at the heart of this year's grading".