Room treatment is the answer (of sorts). Baring that you can position yourself near a wall / corner and sing out into the room with the mic as close as possible. This should a) give a greater balance of source to room. And minimize reflections since it has (if only in theory) the furthest possible distance to travel before reflecting back. And therefor the most decay. The problem of sorts is not so much the mic or source, it's the reflections. If you don't have concerns about keeping the outside world out, you might try keeping the door open, if only partially and the closet door(s) too. Pretty much anything with a larger chamber behind it than the opening to it. Like pushing your books to the front of the book case to create a chamber behind them. And of course couches, beds, pillows, blankets, sweaters, and other less reflective things help to tame the beast.