It's hard to give advice without knowing what's going on, like the Cat said, but when I'm at the end of my rope I practice trumpet lol or just go to bed, or play video games, whatever I can to basically get away from it for a while...sometimes you just need time for things to settle before you can move forward from what's happened.
Things can certainly seem bleak, I've definitely been there, but the sun always comes up tomorrow, it always has at least, and tomorrow's another day, another opportunity for something different, something old, something new. Life is worthwhile, and there's always another option to whatever you're facing. Just keep pushing forward.
There's always more to give and even at the "end of the rope", if you look hard, I think you'll see that the rope continues on for much longer than you're anticipating. You're stronger than you think, you're probably further up the rope than you think, and whatever it is, you can get through it. People are amazingly resilient.
Good luck with things, you've surely helped a lot of people on this site, I hope the good you've done comes back to you :)