Have clothes and carpets become impure due to doubt about water reaching the site of impurity after washing, knowing that there are purity-related obsessive thoughts?

The cure for obsessive thoughts is to ignore them and not pay attention to them. The default state of things is purity, so do not rule something as impure or that impurity has transferred unless you have absolute certainty. If you are certain that a specific area of the body has become impure, it is sufficient to pour water over it until you are reasonably sure the impurity has been removed; a full ritual bath is not necessary. Pure drops of water on a pure spot do not render it impure, and walking on an impure spot does not transfer impurity unless it is actually impure, not just an obsessive thought.