At 19, you’ve had more sad, unfair, and traumatic experiences than people many times your age. It’s not at all surprising that your self-esteem is low and that you are so insecure. Your friends are right. You are not in any shape to make a strong positive relationship with anyone. You first need to make a strong positive relationship with yourself. That means getting some therapy to help you recover from all the trauma and to recover the self you are meant to be.
You do have a core of strength. You broke up with a very bad boyfriend. You got clean. You are still willing to try for love. That’s actually pretty amazing. Give yourself lots of credit for that!
You may feel old and weary but you are only 19. You have plenty of time to find a partner and to make the kind of relationship you want and deserve. But if you want to do that in a healthy way, and if you want to feel good about yourself, you need to do your personal work. Please continue to take care of yourself by finding a therapist.
I wish you well.