When I was around 13, my father moved out the same day I started at a new school. He had cheated on my mother with my now-stepmother (half his age) and their marriage had been hellish for more than 4 years before that. He was explosive, narcissistic, and controlling and my mom was mentally ill, codependent, and very neurotic.
I was an awkward middle-schooler who didn't know anyone at my new school, my dad's new girlfriend was a homewrecker in my eyes and her daughter (older than me since she was a teen mom) was absolutely horrible to me but neither my dad or his gf was willing to do anything about it. In fact, she's still their favorite.
Because the custody battle was ongoing, both my mother and father would try to manipulate me and paint the other as a terrible person who didn't love me. Problem was, I got that from both sides, so I thought they were both terrible people and nobody loved me. They refused to speak to each other, so I had to be a go-between. Everytime they did come in contact, it turned into a screaming match.
I got severe depression and developed a binge-eating disorder as a response to the chaos. It got so bad, I had to take a year off school and stay in a psychiatric facility. I seriously contemplated suicide. I didn't see any end in sight.
After completing a year of treatment, though, I realized that I couldn't change a lot of the negative things in my life, but I could change how I reacted to them.
A lot of the problems with my family are still there today, but I no longer let my life be dictated by them. I go to an out-of-state college, I pay my own bills, have my own phone line, and manage my own affairs so I have minimal contact with them and they can't hold things over my head. I've lost all the weight and recovered from my depression and picked up a few new hobbies as well. I've learned you can love someone and still set healthy boundaries. Now I set the terms for my relationships with them.
Today, I'm 21, happy and healthy, and dating a great guy. I have a great group of friends, and I'm about to get my degree in molecular bio. I think about where I was before and all the great things I would have missed out on if I had killed myself back then, and it's hard to imagine.
It got better. Part of that was that I made the decision to make things better for myself and to derive my own self worth (not to downplay psychiatric treatment, though). I think that when you go through these periods you have to think about it like, if I resign myself, I have a 100% chance of failure. BUT, if I keep going, there's at least some chance I could end up really happy, no matter how small that chance may seem. And when you frame it that way, I think the choice is obvious.