How do you interpret the feedbacks of my boss
There are certain conventions on how to structure thoughts, write texts, present information, and give talks. Find out and learn them. A first step is to ask your supervisor for specific advise, so you can improve these skills.

For example, is is common to finish sentences with a period and to group sentences together to form paragraphs. Note that practically everybody does this. It is a convention to efficiently convey ideas by giving the reader some expected structure she can hold on to. If you don't do this, this already sticks out as part of a "bad presentation". So, learn what conventions exist and use them.

This may help to address presentation and writing part:

http://www.wisdom.weizmann.ac.il/~oded/R2/re-writing.pdf

http://www.math.wisc.edu/~ellenber/mntcg/TalkTipSheet.pdf

PS: This should have been a comment rather than an answer as it only addresses one aspect. I don't have enough reputation to comment.