START WRITING
The worst thing you can do is avoid this skill, because eventually you'll HAVE to do it! The way to overcome the fear, is to confront it, simply sit down and start. Even if you don't eventually use what you've written, to improve you must practice. Write now there's no limit to rewrites, so don't worry too much, but take the opportunity to review and rewrite.
Remember to PEE, make a Point, support it with Evidence, then Explain it.
Use phrases like 'for example', and 'this means that' to introduce your analysis.