You get points just for having realistic temperature desires. I know far too many people who would be absolutely horrified at the prospect of having to try to survive in the withering heat of 76 degrees.
Add insulation to the underside and back wall of the dragon's tank. If his tank is in a corner, insulate both sides that are against walls There's no point in letting that heat leak out any faster than it needs to. The thermostat will adjust the heat so the dragon doesn't overheat but meanwhile the tank will be pumping heat into your room a bit slower.
Look into whether the dragon needs the heat lamp all the time, or if providing him with a hot rock would be more effective. The hot rock will leak a LOT less heat into your room than an entire hot tank.
Turn the ceiling fan off when you're not there. It's only moving air, it doesn't actually cool anything. Moving air blows your heat off YOU, but does no actual cooling below ambient temperature.
Turn off the gaming computer when you aren't playing. Don't sleep it, turn it off.
Place a box fan in your doorway, pointing in. Set it on LOW. THIS fan you may want to leave on all the time. Cool air will blow in at floor level and warm air near the ceiling will flow out at the upper part of the door.