Hello
I'm guessing you kind of already have your topic, you've just not refined it? Even if what you have right now is broad, you still have your topic, you just have to pick out what is most important to your area. From all you reading is there nay crucial gaps? Anything that should be explored further? Any theory you think needs further study?
Start broad - what do you know about your area. What particularly interests you within that area? Then drill it down to what you don't know.
Another good way I used was to look at all the knowledge you have and ask it questions, you'll soon finalise your topic that way
Good luck