Can't Explain It...

According to my mom, who just revealed to me, big things was expected of me. I was their  "genius baby". I am good at what I do or anything I set out to do, I learn fast and excell at it. My present problem is, I let myself down. All of the time. I don't understand why I don't keep my confidence up. I would start a project and dont complete it or take forever and a day to do so. Even now at 47 years old people ask me why I have'nt done more with my self/life with so much potential I had/have. I've lost friends and relationships because of this claustophobic  fear of failure. It is a thing that hurts my money making potential and it is a frustrating thing to recognize it and not know how to beat it. I think it's a form of depression but I don't want to take a med for it ( don't like chemicals in my body)...it's just killing me. I teach my children about self assurance and give them the positive enforcemnet to keep them going but I can tell they see my greatness and wonder why we don't have more, why I have't done more. This bothers me to the point that I shake at the thought when I see that time is drifting and I could be happier, and more comfortable just on the stregnth of what I have the power to produce, but I just freeze myself. I'm an underacheiver and I can'y stand myself for it...