I am slightly homesick

I guess...I am not sure if this grumpiness is due to sleeping too much or homesickness. It feels more like the latter. If so, where am I homesick for? Not for Germany, nor for Turkey, maybe for the US. As soon as I arrive Germany, I will visit Starbucks. The Starbucks shop in Turkey does not give the same feeling with Starbucks at "home", again not knowing what home is.