I think it is genetics, two of my brothers suffer with anxiety and low mood, as does my mother and my grandmother. Difference being they all think this is how their lives are and do nothing. Before all this happened I was a happy and outgoing person and cannot forget that. I have not lost myself and thats been a big help. Try whatever makes you happy and do whatever makes you happy. CBT is good and there are lots of useful websites and support out there.
Living life to the full.com is where I did my CBT. X