When I was younger I was as far down as you seem to be. 11 years later and I'm still not where I think I want to be in my career and I don't even know what my skills even are but I'm still here. The world didn't end. I wasn't disowned by my family, etc... I realized that _only I was upset about my life, nobody else cared_. Once I wrapped my head around that things got a bit easier.
I still have my moments- I'm a CISSP and in fumbling an easy interview question about packet capturing for a job you spent 6 years doing before- but in the grand scheme of things it doesn't matter. Life ain't always rosey but it's not always caca either.
You'll never know what comes next if you walk away before the show is over, and you don't know what's next until it happens.