What is the ultimate source of such self-doubt? Psychological theories look to early childhood, the family, various “developmental tasks,” “learned behaviors” and so on. But “Torah Psychology” points to Adam and Havah’s disobedience in Eden. Disobeying G-d, they simultaneously created in themselves a wrong belief that they were separate from G-d; that they needed to “hide” from G-d. Denying G-d’s presence to themselves led to fear; fear led to a desire to find some way to re-establish a sense of security separate from G-d.
This world (or universe) in which we live is actually “Eden,” when seen from G-d’s viewpoint. We know this from Isaiah’s vision of the angels singing: “The whole world is full of His Glory.”  Eden never ceased to be Eden. The world isn’t “less filled with G-d” just because we don’t see G-d in the world and the world in G-d.
The Midrash  says that before their disobedience, Adam and Havah saw a light in which they could see “from one end of the world to the other;” that their faces “glowed.” This is our “natural state.” All of us should be filled with light; glowing with health, joy and love.
We could also look at “Eden” as an internal, cognitive state: As the Talmud says: 
“Four men entered the Garden: Ben ‘Azzai, Ben Zoma, Aher, and Rabbi Akiba.
Ben ‘Azzai cast a look and died.
Ben Zoma looked and became demented.
Aher ‘mutilated the shoots’.
Rabbi Akiba departed in peace.”
The Talmud understands “Entering the Garden” as a cognitive experience:
Rashi explains that “they ascended to heaven by utilizing the [Divine] Name, i.e., they achieved a spiritual elevation (Tosafot, ad loc) through intense meditation on G-d’s Name]” 
The Tosafot (medieval commentators on the Talmud) said: ” [They] did not go up literally, but it appeared to them as if they went up” [i.e. it was a cognitive, rather than a sensory, experience].
The same loss of awareness that led to Adam’s and Havan’s fear, led to Pharaoh’s ignorance of G-d. In that ignorant denial, Pharoah’s heart was hardened. Without an awareness of G-d, we’re all capable of Pharaoh’s irrationality.
The solution? Awareness of G-d:
“When we give ourselves up to the contemplation of G-d, our soul takes us into a region beyond our present physical world…We transcend, we go beyond the limitation of finite thought, and we draw therefrom power, strength and wisdom…If we have been nervous, tense or worried, we can, in a few minutes, cause ourselves to become calm…It is a deliberate and conscious change from our daily thinking to a communication with the infinite, through our soul…It has been said that we can experience union with something larger than ourselves, a sense of oneness with the power beyond…in that union, we shall find our greatest contentment and peace.” 
The perception of ourselves in G-d and G-d in ourselves, of ourselves as “part” of G-d, is the surest protection against our own irrational fears and insecurities – “G-d is my Rock…” 
G-d’s own Presence would have given Pharaoh the supreme security that he sought.
It can do so for us, today, too.