Autosexuality is when one experiences sexual attraction exclusively towards themself.
History
Autosexual was first used as a very specific term used by Bernard Apfelbaum, a PHD graduate in clinical psychology in his work on the book "Principles and Practice of Sex Therapy.", although he considered it as a sexual abnormality but often autosexuals do not seek out sexual relationships as it is simply a way of life and how they feel about others, it is strictly the attraction to yourself and is not a psychological abnormality.
Etymology
The prefix comes from the Greek term 'auto', meaning 'self'.