What's Next in Medical School?

In my country, medical scols six years, and we finish it, and then we go directly into residency. So the first three years, i was happy. I didn't even know what i was doing there. After year four, you looked up and you couldn't see,. You were ok, like climbing one handhold at a time. And then the moment you look up and you realize, o crap, like this tree doesn't end yassi, you became unhappy, exactly. That's when it hit me. If you want to be happy, what should you do?