Today's my birthday and I just want to die. [22/f]

I'm not going to kill myself, but honestly, It's all I've been thinking about ever since my dad died. (Which was about 3 months ago. He had colon cancer, and it was fast and traumatic.) Since then, something then in my brain changed. I have had a deep sadness. Also, I'm on medical leave at the moment which doesn't help at all my depression. I lay in bed constantly staring at the ceiling, imaging ways to kill myself. Wondering what the point is to everything. Whats the point of even making connections with people anymore. Hanging out with friends isn't fun anymore. Fake conversations about what there favorite movies are, and constantly bragging about how great there lives are. I don't give a shit anymore. I just don't know how to deal with it anymore because my friends are actually good people. i don't want to hurt them. Im just so sad and shitty, I even wrote a sad and shitty song about it. I can't get out of bed, my muscles hurt, my brain hurts from thinking about how I hate everyone, and how I hate myself,I just want to disappear. Fuck.

edit:typo, i'm actually 23 today.