On a cold night in Franceville, the Black Stars saw their hopes of lifting their fifth continental title crashed by Cameroon, who emerged 2-0 victors in the semi-final fixture.
Michael Ngadeu-Ngadjui put the Indomitable Lions in front on 72 minutes, before Christian Bassogog sealed victory on the stroke of full-time.
"I am more than unhappy," Grant said.
"We wanted so much to be in the final. We did everything to be there, and in the second half, we completely dominated.
"Congratulations to Cameroon of course, but we were the better side and we lost.
"I think we are successful even now.
"We didn't win the cup, but we have had a good tournament.
"We were the better side, and in the last tournament [two years ago in Equatorial Guinea], we only lost on penalties [in the final to Cote d'Ivoire].
"It is a good generation, a new generation, and I think they will win a lot of titles."
Grant was appointed Ghana coach in December 2014, just two months before leading the side to the final of the 2015 Afcon.
Although the Black Stars were not new to the Afcon final, having twice reached the stage prior to Equatorial Guinea 2015 since their last continental glory in 1982, the Israeli was hailed for his 'immediate impact'.
However, the former Chelsea boss has taken a lot of stick for poor results and lately unconvincing performances.
With his contract set to run out by the end of February, there have been questions over the 61-year-old's future.
"My future is not important now," Grant said.
"What matters now is that we lost after a very good tournament."
Ghana take on Burkina Faso in the third place playoff on Saturday.