I've noticed my kind, caring nature has cause more pain and depression than good. People treat me like trash, 3 weeks ago my first love left me after disrespecting me, insulting and treating me like trash because I tolerated everything. She was narcissistic so my personality was always taken as weak and she would do whatever she wanted. 

Lately I've noticed all the trauma people cause is altering my personality. Making me stronger, less caring and it has increased my self worth and confidence. My first love taught me a serious lesson. I never even want to love or be in love again. 

Anyway I just want to find out. How can I have a no emotion type of personality? How can I care less? How do I develop a personality that doesn't tolerate bs and has a strong sense of self worth?..... people might say don't change or don't alter your personality but please understand I've had enough, I've been through so much, I'm enduring so much trauma and depression. 

I'm only trying to protect myself and my well being, to put myself first and do what's best for me for once. I just want to have a stronger sense of self worth so that I'm able to treat myself better and that also means I'll never let anyone treat me like trash. This is only to protect the little amount of life I have in me. To protect what's left of my personality, to protect the little bit of love I have for myself. People have damaged my soul, I'm only protecting what's left yk

I hope this makes sense. Any advice for me? I appreciate any responses to this in advance. I'm only 19 btw.