Struggling with essays

I’m really struggling to come up with a theme for my literary review and, thus, my contextual review. There are so many interesting topics, which seem to disqualify themselves for various reasons:

• How do they tie in with what I’m practically pursuing in my MA?

• How can I narrow it down to a meaningful 750 words?

• Isn’t this an old hat that has been already covered umpteen times before?

• Am I really this interested in this topic?

• Will this not totally lead me off into a direction I don’t want to take?

Well, obviously it should start with reading and informing myself and then some interest may emerge from my research. However, it may also just throw up an overwhelming number of possibilities and by the sheer quantity will make the decision process even more difficult.