I'm so sorry, Saiyouri, that's a terrible situation. Your ex appears to be dangerously uninformed about mental health. I really hope your mom can help your daughter out. I've been suicidal and self-destructive a few times in my life, but at least I had a supportive and understanding family to get me through it. At least she has you, even if it's complicated.
This might not apply to your situation, but I've found this hotline useful.
http://www.crisistextline.org/
It's called Crisis Text Line and if you or someone you know is in a crisis you can text them. It works a lot like a normal hotline, except you use text instead of calling. It's a free and immediate way to get in contact with a trained crisis counselor. It's just something that's good to have in the back of your mind, just in case.