You should immediately move without wasting even a single minute. Because, if the appeal period is over, he will be entitled to go for another marriage and if that happens, there wlll be no use for your to go to appeal, because, as he has already married the court would dismiss your appeal.
I hope you understand the urgency. Without trying to find out the methods to obtain certified copy engage an advocate and he will do each and every possible thing to get the copy immediately and prepare an appeal for High Court. In the absence of certified copy also, the advocate can seek the stay of the operation of the decree before the High Court.
Wish you best of luck.