Hi Christine,
I'm new to this forum and just see this message, so hopefully still of use:
Reserve 1 weekend (at least every 6 weeks) to escape to nearby Miri or another 'deal' to explore what's around Brunei.
Seek membership at the Royal Brunei Yacht Club, IMO the only "expat social ground" where you always bump into somebody you know.
Colleagues from work, parents at school: very diverse group here in BN, incl. some interesting characters for sure.
Hiking in the several parks: take GPS as back-up if you tend to explore the more lonely paths (99% safe, but don't get lost)
Beaches: few facilities, so back to basics and ensure you wear bug-spray for sandflies
Entertain at home: if possible you have a pool and can invite people over, to enjoy a drink and improve the BBQ skills
Hope it gives you some ideas.
Cheers,
Paul