Regarding Divorce

Hello Sir/mam, In the year 2012 I had separated from my husband by way of a compromise agreement after waiting for a required period of 6 months. The agreement was on a stamped paper and notorised. In the agreement is mentioned that we both are free to take any decisions and nobody would interfere in our decisions or day today life. Also is mentioned in the agreement that I will have the custody of my son and he will not have any claim in future. Now I want to get remarried. I wish to know that , if this compromise agreement is enough or do I have to file a divorce case again ? If yes ,what is the process to file for a divorce. Please note that I have sent a formal notice to my ex-husband for a mutual divorce. But I have not received any reply to this notice. So please advise what is the way forward. Can I get married again based on the compromise agreement of 2012.( without the other party creating any problem later ) Or do I have to file a divorce case again and wait for 6 months ? Please also advise what is to be done if the other party does not reply? Is there any way to get a divorce quickly ?