Kitten,
Apart from now, the other time that I had depression very badly was when I was 24. I was an expat at the time and had accsess to great medical help. I hid my depression from all behind a smilie face. Looking back i dont know how I managed that. Couldnt do it today as the tears come endlessly. Trying to hold down a Job when you are young and want a career, etc whilst trying to manage your illness is so hard.
Be strong, you will get through this and even though, like me you feel alone, there are probably a lot of people you know hiding their depression like you.
Hang on in their and before you know it you'l be an old duck. This is an illnesss that knows no age restriction young and old we are all in this together. x