Hello,
Thank you for posting your question.
The procedure of obtaining divorce and getting re-married is separate in Hindu and Muslim personal laws.
However, there is no such thing as cancellation of divorce. In case you wish to get together with your ex-husband, you will need to re-marry. And that procedure is also different in both Hindu and Muslim laws.
Hence, in order to further assist you we need to know your religion so as to find out under which personal laws you are governed.
Regards,
Nishant