What is the ruling on the spread of impurity throughout the house, and is it permissible to pray and recite the Qur'an therein after touching its contents, knowing that the cause of the impurity is the questioner's urination on the sofa without immediate cleaning, and this situation has persisted for more than two years?

The default principle is that impurity does not transfer, and purity remains. The questioner's doubt about the transfer of impurity to all household items is a result of obsessive thoughts (waswasah). Therefore, she should ease up on herself and beware of succumbing further to these obsessions. Household items are presumed pure and do not become impure merely by being touched. It is not prescribed to wash clothes every day just because someone has touched them. As for the mattress on which urine fell, it is sufficient to purify that specific spot.