heating properly....You can test it with an oven thermometer but I would just bet that you need someone to check out your oven....
When you bake other food does it cook properly or is it just meat loaf?
When I bake my meat loaf I cook it in my 10inch cast iron skillet...Comes out delicious.
Just a note..I always spray the bottom of the skillet with Pam so it won't stick..