In general, a fixation is an obsessive drive that may or may not be acted on involving an object, concept, or person. Initially introduced by Sigmund Freud, a fixation is a persistent focus of the id’s pleasure-seeking energies at an early stage of psychosexual development. Oral, anal, and phallic fixations occur when an issue or conflict in a psychosexual stage remains unresolved, leaving the individual focused on this stage and unable to move onto the next.
Shame, Guilt and Embarrassment = sexual difficulties
The whole process of sexual reproduction is odd - not just because of the sheer power of its instinctive drive but also because it is something of a puzzle as to why it exists at all. Many animal species are what is sometimes referred to as 'intersex' - that is, they are both sexes at the same time - and there are around 4000 species which are all female and reproduce without any form of sexual activity.
Rebuilding Relationships
What could be happening if female sex drive starts to fade
Within a stable or steady relationship, the female all too frequently discovers that her sex drive starts to wane after a relatively short while. A cynic might say that this is because she has finally snared her male; in reality, the truth is more likely to be that her male simply makes less effort to create arousal and enjoyment for her. This is not necessarily selfishness - although it doubtless is the case much of the time - for it is rare indeed for a male to be taught exactly how important this is.