I only corrected 2 things:
"I am writing to you (to provide you) the latest news both in terms of my postgraduate course and my efforts regarding the Greek State Scholarships Foundation."[...]
[...]"I am working now on my Master of Science Thesis in order for me to (finish) the course."[...]
What's in between parenthesis is what I can help you with. I'm not a teacher; I'm a student.
Sometimes it's hard to spot mistakes because we never really know what the writer actually meant.
Remember that there may still be things to fix in those sentences.