One of the hardest parts of doing your literature review is actually knowing when to stop.
As professor Liesbet van Zoonen points out in her video When to stop reading and start writing (4:10) it can be a matter of indecisiveness and lack of confidence. You don't want to miss anything that's possibly relevant, so you keep on reading and the literature review process never really seems to come to an end!
At some point however, the constant reading has to stop for the writing to begin. You'll have to consolidate what you have into a submissable form for your supervisor.
For tips that possibly work for you, see the links under Suggested.