Thanks for recommending k6! Disclaimer: I'm involved in the k6 project, so quite biased :) I think k6 is the best tool available if you're a developer who wants to automate load testing. But I also actually wrote a review article comparing 11 different open source load testing tools - http://blog.loadimpact.com/open-source-load-testing-tool-rev...
It seems you could excel at one thing if you could choose between the three. Pick one up, get a medium job and then excel. You're no failure, don't worry about that. And yeah, maybe get some perspective working in another country? Not sure what you mean by mentally exhausted (differences between individuals I guess) but your three months inactivity should have reduced that stress. You can't be doing 'no thing' even though you don't work. Take it easy, learn some new stuff, quit habits increasing stress. That kind of things should help I guess.
I'm not on fb. I read in the comment from the spokeswoman that the distinction cannot be made by their robotic rules. So I believe this illustrates a limitation of their AI. And they don't care so much about the people than their algorithms. Just an opinion.