Say what you'd most like to hear...
Sometimes we just need to hear a certain phrase for us to feel comforted and happy.
Say something to yourself that you'd most like to hear right now. 

I know what you feel is real and because your sister is going through a really hard time doesn't mean you cannot.
I like talking to you.
Im here for you.
Positive changes take time and practice. Yes, now dealing with negative thoughts and emotions is an enormous challenge. But if you don't give up, it will become easier and easier and someday being calm and fully present in the moment will be your normal state.
It's not you. Really, I don't blame you for anything. You are an amazing woman and I do miss you.
~ Let it go......the sweetness of life is waiting for you
You look beautiful my love
You can sit here, count the days until you are 18 and fly to some country and kill yourself legally or take a chance and live a little. Take that step to adulthood. Its a large step, I know, and there is no going back, but you can do it. You won't regret it.
You've done so well and have made it so far. You've been so strong! I'm proud of all the things you've accomplished - even if you might not think they're the greatest.
Please stop beating yourself up. You don't deserve all the things you're doing to yourself, trust me.
I appreciate you being in my life, and I'd like you to stay. I'm here to help any way I can. I'll hold you up and be strong for you. We're in this together.
you've come so far and i'm so proud of you
Be happy and kind no matter what....
I love you and we're going to be OK.