And, you need to somehow recap all your central points without simply repeating yourself. I had a conclusion section in my EE that went on for about a page and a half where I briefly summarized my arguments and I answered my question, and stated a few questions that might arise from how I answered it.
Just try to get help from various sources. They must end knowing more than they did at the start.
The Conclusion should restate the main argument. Shakespeare uses both the meter and structure of the sonnet to maximise the effectiveness of this metaphor.
Use as many sources as possible. No one will see it but you.