This does not even begin to explore other causes such as birth control pills, medications for depression, anti-anxiety and many others. Then there are of course physical contributors such as medical conditions, poor diet, lack of exercise and sleep. It can be a challenge to even know where to begin.
Read our article on Getting Your Lover in the Mood for Sex for a place to start. It does not have to be difficult and in most cases, it can be downright fun!