Taking a few days break to do whatever you enjoy most, away from study and/or work sometimes help. The short period may allow one to reflect over things that may not have been going the way we desire as well as helping us to refocus. I will encourage you not to give up. Consider finding a way to contact your boss at the Lab, either personally or through someone still working at there. Let the boss understand that you were probably going through a lot at the time and asking for opportunity to get back to work. Working at the lab as you are progressing with your PhD is highly likely to boost your motivation the more.
Good luck