Douglas performed 'I Look to You', originally sung by Whitney Houston, in memory of his brother who committed suicide. Douglas has also previously spoken out about attempting to take his own life and has also said that "life has not been great".
Speaking on the show, Douglas said that he performed the song at his brother's funeral, but after the verse and chorus he "couldn't carry on".
He added: "Tonight I'm going to go out there and finish the song in dedication to my brother."
Mentor Nicole Scherzinger began to cry during his performance, and said it was "such a blessing" to have him on the show.
Asked by presenter Dermot O'Leary how he felt afterwards, Douglas said: "I just feel like I let go of something. I don't know what to say."
All four judges also praised Douglas following his second performance of Etta James hit 'At Last'. Of his experience being on the show, he said he had enjoyed it and was glad that he could demonstrate that "if you have been through something, you can pull through no matter what".
Watch Jahmene Douglas perform 'I Look to You' on The X Factor below:
Photo gallery - The X Factor semi-final:
Copyright: Ken McKay/Thames/Rex Features