Divorce and second marriage

I married a classmate during my MBBS. I am a Muslim and she was a Christian. We married first according to SMA and sometime later according to Muslim laws (Nikah) where she also accepted Islam. We lived a relatively happy married life for around 30 years. We also have 2 grown up kids who live separately at present. Around 4 years back my so-called wife decided that career and money is more important than a husband of 30 years. She deserted me one fine day on the pretext of travelling to Europe. She never came back. After a while she sent me a notice for divorce through some lawyer and when I tried to meet her she got some restraining order from court. For almost 2 years I tried for reconciliation but she didn't agree . Its 4 years now. We never met or talked but were in touch occasionally through Facebook for kids sake and needs. At present we live in different countries and both have a successful professional life. I'm 54 now and after living a lonely life I feel the need to relive and restart my life. I plan to marry a Muslim woman now. She is not an Indian though. Now the issue is I'm still not completely/legally divorced. I asked my ex for permission to remarry or for divorce by mutual consent as per the papers she sent me 4 years back. She has somewhat agreed to the later although a bit reluctantly as she probably thought that I would die a lonely life. What's my best option for a fast divorce. Also what are the requirements if I plan to marry a non Indian Muslim lady.