After a bit of struggle and a lot of waiting, all the administrative side is now finished.
Just got a call from the embassy telling me the insurance had confirmed the incineration authorization and booked the incineration that will happen today (30th of Mai 2014) at 18:00.
So I can now go to it and prepare my exit of Vietnam. Next I will be going to Singapore and Malaysia for about a week and then come back to France bringing back the ashes to the parents.
Which basically means I am stopping my trip. I wanted to continue and actually tried, but as a friend stated, it is hard to go to places and do things alone when you had planed them with someone else.
Thank you to all those who messaged me for support, it was greatly appreciated and much needed!