I recently found this thread and site from a google search. I decided to join the site.
I have gone through similar issues in my own life. I am diagnosed as major depressive but I may actually be bipolar.
I was identified as gifted in elementary school as well. I have had a career as an engineer and been interviewed and published at international level. I have never been able to keep it together long enough to reap the rewards of the hard work. Grandiosity, fantasy and ego were the things that held me back. I am now in my early thirties and recently have been declared disabled (receiving SSDI). I am in immensely in debt; lost my kid, home and many possessions due to a nervous breakdown. My point here is that raw talent does not equate to success. I have been struggling with this for a long time. Success is about the whole the package. It is about the hard work and more importantly the discipline. I think it takes more discipline to succeed if you suffer from a mental illness than if you were a person without such an affliction. I am now seeing that my journey is as much about dealing with mental illness as it is about a successful career.
Being "gifted" is exactly that, a gift. Having a gift of talent in no way entitles you to success. Considering all the talent and intelligence that you have, apply it to overcoming you illness.