I used to work handling insurance claims and most of the stuff you get to "secure" your home is of little value. Most interior doors have only a 3/4" thick door jamb and no matter what kind of lock you have on it, the door is going to open. Even a heavy gate that people put on the outside of a door is only as good as the few screws that hold it on to the trim. A decent crow bar will rip it down in a couple pulls. Even if you were going to get a safe door to put on your room, a foot can go thru drywall and most plaster with just as much ease as going thru a cheap door. The best way to make your room secure is to screw T111 plywood siding on all the interior walls of the room. Make sure it is screwed to the studs, and laminate the inside of the door with it as well. Screw and glue it to the door. Make sure that all of your existing hinge screws are long enough to go into the studs and not just the door jamb and install surface mount dead bolts at the top and bottom of the door on the latch side. Make sure your screws go thru the plywood paneling and into the stud. I see no need to attach anything to the floor and really no need for the gate. This way from the outside of the room it looks like any other door in the house but inside it is solid.
The final thing to do is see a doctor about your paranoid behaviour. Even with all these steps, a sawzall would get someone into the room in a matter of minutes if they really wanted to get in.