I'm also aussie, single and 40!!! (don't quite know how THAT happened :-)) As for living in Qatar (I've been here for "a few" years), there are heaps of things to do BUT you have to get out there and find them.
Things that drive ME crazy -
Ramadan - nothing opened when you want it to be
Humidity - August / September seem to be the worst months for that, but the rest of the time it's just HOT!!!!
Beige - everything seems to be this colour - inside AND out
Drivng - crazy, scary, frustrating. But once you master the whole "on the other side of the road" thing, and be patient (traffic jams a daily occurance), it's easy enough to do.
Things I like about it:
Generally, you can get whatever you want - so long as you know where to find it (including Vegemite. Yeah!!!!)
Most of the locals are friendly and will go out of their way to help (unless of course they happen to be in a Land Cruiser etc, then they expect YOU to get out of THEIR way. Refer to previous comment about driving)
Cultural experiences - getting better all the time
Sporting events - some of the "big names" come to Qatar to play all sorts of games. Entry to these used to be free (i think there may be a small charge now)

Good luck! Most people either love it or hate it.