I understand this feeling. Feeling like you've failed everything. You're not alone. Don't give up hope. You've been so strong, gotten so far. You've gotten through every storm life throws at you. If life couldn't break you then, it can't break you now. Do you have anyone to talk to? We all need someone to help us through the struggles. If not, what I like to do is imagine someone. An imaginary friend. That most definitely sounds childish, but it helps. Maybe it'll help you, too.
Don't lose hope. You're important. We all make mistakes. Nobody's perfect, and that's what makes us all special and unique.
You deserve to be here. Every flower in a garden is as beautiful and important as the others <3