I completely agree about the need to slow down a bit. Work has really been pushing me hard lately. This week in Korea (also for work) has allowed me to slow down enough to realize just how much I've been missing. When I get back, I'm going to set some much stronger boundaries for myself to ensure there is enough time for myself & family. Maybe also get some shop time in too.
One option for your too-small window could be one of those "portable" A/C units. Rather than hanging out the window, they are free standing and have an exhaust vent similar to a dryer. You'll pay a premium over a window unit & it will take up a bit of floor space - but you may save in the long run with time & materials over cutting a hole in the wall or resizing the window.
Measure with a micrometer, mark with chalk, cut with an axe.