Go into that interview confident that you are the right man for the job. I know it's been rough lately and at times you may have felt like a whipped dog, but don't let those emotions affect your future.
It sounds like you have a pretty steady head and can prioritize things that are important. I really admire how you've been able to press forward with your studies. Good luck with the job interview!
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!
