Yeah SAD can be a drain. Humans are great and we learn to adapt. That is interesting about your mother and the homesickness. I must admit I have probably lived abroad for over half my life and I never got homesick, probably because I told myself why leave home lol!
Ah yes the extremes of heat can be a pain, at least here it is never too hot, and this part of Scotland never gets too old either. It is very rare that we even see snow for example!