If you think that 4 ULRs per month would be easy you are in for a shock.
900 hours per year in LoCo short-haul may be physically demanding, sleep-wise it's a somewhat assured regularity.
The other major factor out here is chronic stress. In your home country you go home and are in your comfort zone. As an expat (especially in certain countries/cultures) you never really get away from work. You have all the 'annoyances' of a country that is very different from your own (traffic, fear culture, corruption etc) and this slowly builds up in the background without you realising it is affecting you. Marriages that do well at home easily break up. You my find yourself angry with family, neighbours and work. Most people are here for selfish reasons and will do anything to protect their own little bubble... especially your 'leaders' at work. It is most definitely not a nice 'atmosphere' to be involved in.
And it IS getting much worse by the day. It's rat-eat-rat. Period.