First of all we need to understand that what you have described may be entirely normal. However, in certain instances, when you think there is no harm in using others toilets but you still are not able to, because of your own thoughts, and you realise that these thoughts may be senseless and irrational, then it is time to visit a psychiatrist and take help. Certain people who are very concerned with cleanliness, can have concerns with and doubts about locks/doors being properly locked, lights being switched off, things kept in a particular order/symmetry, and also preoccupation with dirt/germs, which may lead them to do certain acts repeatedly like washing excessively, checking repeatedly, which may cause them discomfort but they are unable to stop it or control it. Evaluate yourself, and if you fall into this category don’t hesistate to go to a psychiatrist, because these symptoms can be well helped with appropriate medication and behaviour therapy.