Wow. Did I write this post? Seriously, I feel a lot of similarities in my own life, right down to the age.

You don't sound socially isolated to me, but if you're worried about it (that 'nagging feeling') I think it would be super cool to find an interest that's JUST FOR YOU. Not something that involves your husband or acquaintances, but something totally different, with new, interesting people.

Example: I went to some local "Cactus Appreciation Society" meeting once. It was so weird and fun. Not going again, but it bolstered my confidence, and I can see how i'd benefit from meeting people outside my circle.