Hello,
This dizziness which is present when you are in the house and disappears when you go outside can be due to air borne allergies to dust mites or mold. Please contact an allergic specialist and get skin tests for allergies like skin ***** test done. In this a small amount of allergen is introduced into the skin of the forearm and the reaction of the skin is noted. If there is any redness then that person is allergic to the allergen introduced.
You can also get blood tests like RAST done. If you are allergic, then treatment is directed towards allergies.
I hope it helps. Take care and regards.
does anyone living with you have any of the same symptoms? if so, could be carbon monoxide poisoning.