I felt that way for 16 years. It was horrible.
My pathway out was realizing that I didn't even want life to get better for me, I didn't even desire it. I was letting my care for others fully take over my own desires. I was quite literally living for them.
Did I have faith life would get better? No. Did I want to it to get better? If it meant that I wouldn't hurt my loved ones, yes.
That was the wake up moment for me. I had to grieve the fact that I actually didn't want to end it but only on behalf of others. I couldn't even stand up for myself.
From that moment of realization, I took time to practice wanting to live for me and only me, not for them. They're important, but they're second to me. I am first to me. And of course they're included - my loved ones make life better for me. I want them around too, so my life is better. But first, I have to want to live for a reason other than not making them sad. I had to want to live to make me happy.
I am still practicing it. But it saved me.