You bought a nile monitor w/o researching how large they get?
Also, how are you 99% sure that it is captive bred? Nile, Savannah, and Water Monitors are some of the most heavily imported animals and because of that, there is not a huge captive breeding effort going on.
In any event, it sounds like you've got a lot of research to do, based on the questions you've asked. That's why you're here, right?

I guess what I'm saying is I like to see people do research BEFORE they have the animal in their possession.
Here's an adult nile, have fun with your new "pet":