Ok, first as others have said, STOP FORCE HANDLING. You may get a reaction where you think he is calming down, but in reality that will be him giving up and hoping the "giant scary thing" will go away and not eat him. At this size, everything it sees is a potential predator and your not going to change it's mind right away. It's going to take time and a lot of effort, but it will be well worth it for the end result.Food is your best tool for taming a monitor, they are literally slaves to their stomachs.
Best plan I can suggest for you will be to start off by leaving alone for a week or so, do nothing but light maintenance, like cleaning his water bowl, putting in his food dish, etc. then once he stops running for cover the second he sees you, you can start trying to feed off tongs and see how that goes.
Now as for the current setup, it will probably be OK for a month or two as long as it's setup properly. However, you need to start on the adult enclosure as soon as you have the setup in the tank stabilized. Properly supported monitors grow incredibly fast, at least for the first few months, and yours will quickly be too large for a "tank" setup. Please post what your temps are, basking site, cool end, what your humidity is at, and how your measuring these, and if at all possible pictures or your setup and the animal itself if possible. And welcome, by the way.