We are all different.
You can be born with a genetic trend to suffer from anxiety ( this does not mean you will) ,you can learn through nature/ nurture as you grow up, or through trauma during your developing years...
But if you feel you are in a hole, don,t waste time trying to figure out how you got there, spend time figuring how to get out...
Your racing mind can make up stories, good stories leave you happy as you jump on the thought..Bad stories make you anxious as you jump on the thought....
The secret is not to believe everything you think, and especially do not Jump on any thought, stick to the here and now. Your mind is overactive like a deer caught in the headlights, this is why relaxation and meditation can bring you back to reality...
For all phobia suffers, the subject of you negative thoughts is only something your sub- conscious has chosen at the time...It may be health but this is just your chosen subject, if you are an anxious person your mind could have chosen a multitude of subjects....The problem is not your given choice of phobia, your problem is dealing with anxiety, your chosen subject next is just a trigger, convincing you that that is the problem...
The path is hard but the benefits are huge...
Welcome fear ...smile at it joke with it let it become your friend and it will disappear...
Spend time walking in nature allow yourself " you time"..
And most of all look in the mirror Evey morning and tell yourself you are good enough....Learn to love yourself and you are learning to love life...
Blessing