Essentially, yoga means dissolving your identity.
Time and space are just projections of your consciousness.
The purpose of existence is to exist. It is too fantastic to have a meaning.
Once you have access to the source of creation within you, your health and wellbeing will naturally be taken care of.
Self-transformation is not just about changing yourself. It means shifting yourself to a completely new dimension of experience and perception.
It is not sex per se - your identification with the body is the impediment to your spiritual growth.