[MMM]

What do you mean by "master". Do you mean you want to be able to read an engineering manual, or do you mean that you want to be able to communicate fluidly with people. If it is the second, and I hope it is, then you WILL need to have a life, because the best way to learn the language is with native speakers in their country. I think it's a great dream, but if you aren't a "master" withing 1.5 years don't beat yourself up.