Hi everyone - this is a bit of a plug, so hope that's allowed but I recently came across a great site for second wives/partners. Aside from various practical info., it has wonderful forums where you can let off steam, ask advice and so on from other women (only) in similar positions. It does cost, but the fee is very reasonable. The best thing about it is that all members are second wives/partners who know where you're coming from, so you can sound off without fear of upsetting other readers who might be in a different situation entirely.
Have a look, I love it ....
the British Second Wives Club