I have been anxious all my life but where does it come from, why does it continue?
Who is the person in fear, and more to the point why?
I've always been agoraphobic since a child. Do I have to continue to live my life out in fear?
No, you absolutely do not have to continue living in fear.
Your true Self knows no fear—it embraces everything with peace and absolute love, without any judgement or resistance.
This is already your essential nature, it's just been obscured by the many years of false mental projections which you've mistakenly aligned with your sense of self with and have presumed to be true, including all thoughts, opinions, beliefs, memories, expectations, assumptions, fears and desires.
You suffer only from the story you tell yourself, about yourself.
But every belief you have of yourself—such as I am fearful, I am anxious, I am limited, I am lacking, I am not worthy—having nothing to do with your true Self.
Your true Self is forever aware, always there, completely unattached to whatever it perceives—never personalizing anything whatsoever.
Know yourself as a presence of Awareness, and not any of the "personalized" stories you wrap around what your perceive, that you then hide within, and suffer from.
Expose your fraudulent false-self who is suffering. You are not that.
The self you presume to be is merely an activity of thinking. It is not you. This false self-identity is a function of "selfing", an ongoing activity of mind that applies the sense of a personal self onto whatever perceptions appear, claiming them as "mine".
Sure, fear can be sensed, but it isn't "yours". Anger can be felt, but it isn't yours. Sadness can be experienced, but it isn’t yours. You, awareness, cannot be limited by any sensation whatsoever.
You, are free.
You suffer only from personally identifying with this continuity of misappropriated, false thoughts that have created the illusion of You, The Sufferer.
But you are not that.
Observe all of the mental processes that continually stream through mind and realize that none of them are you. But, if you happen to identify yourself as them, they will certainly appear to be true.
You are not any thought—including fear—you are the awareness in which they appear.
Watch the mind and stop it in its tracks whenever it begins to start "selfing". Ignore the thoughts completely, they have nothing to do with you, awareness.
Only identify as awareness, at all times—this is freedom. Freedom from that which you are not, while realizing all that you truly are.
See through the illusion of mind, and you will find... no fear... just an absolute peaceful presence, not relative to anything, not conditioned by anything, just a blissful inner-silence... the calm of infinite consciousness, un-affected by the limited mind.