Hi Lucy, I didn't tell my parents about my depression (didn't know it was depression then but knew there was something terribly wrong) until things got so bad it was obvious I wasn't well, my mum got me to the doctor, I think mum understood a little but my dad never did. It was about 25 years ago when my depression reached the point where I could barely function nowadays people are much more aware as to how crippling depression can be.

I'd try and tell your parents rather than hide it away and make excuses for not going out (I used to do something similar when asked out I'd make all sorts of excuses as I was just scared of going out where there were people).

The more open you are the easier it becomes