How would I define codependency? Giving others too much power over my happiness and self-esteem.

I am in love with one of my best friends. I have been for almost two years. During the time I have given her so much power over my happiness, based on my interactions with her, usually texts. She was in a very toxic relationship. The other woman was not good to her. I was obsessed with wanting them to break up and I told myself it was because she deserved someone who would treat her right. Deep down I knew I only wanted that someone to be me and if she found someone who did treat her right who was not me, it would be painful in a different way.

That toxic person she was involved with broke up with her right before Christmas. She was devastated. I was there for her and helped her pull through it. We texted all the time and grew even closer. I hoped beyond hope that she would realize she cared for me the way I did for her. She knows how I feel about her.

Then about 3 weeks ago she met someone else and fell in love. I was gutted. It hurts to even type about this. It triggered another depression and it honestly felt too painful to keep living. I wanted to die. I prayed for God to take me. I looked up how to commit suicide by carbon monoxide. I looked up how many Advil PM it would take to kill myself.

I am still in so much pain. I cry daily. My self-esteem is shit. I tell myself all the time how stupid and worthless I am and that I should just kill myself already.

But that scares me, too, because I no longer really believe there is any kind of Higher Power out there or something beyond this life. I believe dead is dead.

The woman she is in love with was born right around the time I graduated from high school. That makes me feel so old. Dried up, bitter and unlovable.

I know this is not healthy. I know I am fucked up. I know I am responsible for my own happiness. She is not. I am reading Codependent No More and Uncovering Happiness, the former of which focuses on creating your own happiness and not finding it through others, and the latter which seems to focus on mindfulness and self-compassion.

I have no self-compassion. I hate myself. I am uncomfortable in my own skin. I walk through life feeling apart. Feeling prickly, defensive, over-sensitive and sick.

But it kills me to think of her with this girl. Kissing this girl. Cuddling this girl. Being intimate with this girl. It fucking kills me and I can't seem to stop obsessing about it. How do I let go? I pray and try to calm my mind by reciting things that soothe me, but my thoughts inevitably circle back to her and I am just devastated that she didn't choose me and once I'm there, the negative talk takes over. I'm stupid. I'm worthless. I hate myself. I want to die. I should just kill myself already. Over and over and over and over. I'm tired. I have 3 self-help books to try, but I'm tired. I feel like giving up. Like I am never going to have the energy or follow through to help myself. I'm just too tired.

If there is a Higher Power out there, please help me. Help me figure out how to help myself.