I have depression too.
I think what helps is different for everyone.
What helped me was pushing myself out of my comfort zone, as scary as that sounds. I would try my best to make friends no matter how painful I felt it was. I would push myself to get out of bed. I would push myself to go out even when I wasn't feeling it. If it worked out well, I would thank myself for doing it, I would enjoy whatever it was and I would feel a sense of achievement and be happy for the rest of the day. If it didn't work out well, I congratulated myself for trying anyway. I'd even sometimes buy little gifts for myself to congratulate myself for doing things e.g a new dress or give myself a reward e.g a bath, lazy night eating chocolate and watching films (sounds corny I know, but it works)
As I made a few close friends, I sort of eased up around them and felt more comfortable. I told my closest friend about my depression and she is now sensitive towards it. For example, she knows after a argument that I need to be left alone and don't like to contact anyone. Be careful who you tell though if you're like me and quite private.
Exercise also helped me a lot. I know thats a pretty generic thing to say but it does wonders for your mental health and your confidence. Try to excercise at least 3 times a week.
Take every day as it comes. It is going to be hard for you so don't expect to achieve what you want straight away. Baby steps. I used to reward myself simply just for getting out of bed. It takes time.
Oh and by the way, you ARE normal. Your mental illness doesn't define you. You will be surprised how many 'normal looking' confident teenagers are actually battling the same demons as you. Also, don't expect too much of other people and don't rely on them either. It sounds harsh but this is what got me hurt so I'm just letting you know. The only person who can empower themselves and make themselves happier is you