Writing is an anxious job, putting yourself out there, exposed on paper, and so not many could conjure the strength to finish writing what they've started. And so I don't review my writing unless I've finished a session of writing. So, first work towards finishing what you've started, you can only work upon what you've already done after all.

Being a writer means coming up with new and creative ideas, which is only possible when you give your brain a chance to breathe. In this cluttered world of gadgets and entertainment, it has become quite difficult to have some genuine downtime. But, it's while you're doing nothing that the most brilliant idea will strike you! 

Somedays you'll be writing like there's no tomorrow, and then there will be days when words would be anxious to come out, every sentence would be an effort. Everyone has those days, and in that case, it's best to try and give up at the end, give yourself some downtime, read some new books. Find inspiration, you'll be back in no time. Every writer must go through writer's block every once in a while. It is what it is.