At the risk of getting the thread locked by coming in so late ...
Insecurity vector, what a brilliant term! Mine was my skin. Early changes in the mirror horrified me, and I did everything possible to slow them. From ages 26 to 42, I had regular botox and filler injections, chemical peels, laser resurfacing and more. Not to mention standard non-invasive facials and ultrasonic etc treatments, plus at-home masques, serums, creams. I arranged vacation time around treatments, used sick time, never left the house without layers of different sunblocks. Sixteen years of that, you can do the math.
I bristle at suggestions of volunteering (whether to relativize your own problems or as distraction or as greater good), therapy, and especially gratitude lists. There's a #$%! gratitude list running in my head all the time, and it's nobody's business what I'm doing to pay what forward or whether I'm being of service to a given community. (Also, having been raised by trust-funded do-gooders, I'm very skeptical about what I've come to view as selfish volunteering. But this isn't the place to raise awareness about that.)
In your first post, Dana, you label your struggle "first-world problems," but the first world is where you live. Your problems are *your* problems -- to resolve, suppress or adapt to. That "great husband, interesting career, wonderful kid," good food, adequate healthcare and nice wardrobe aren't automatically nurturing you, at your core. With all that fabulous external stuff going on, is there really sufficient time and encouragement for *you*?
Friends who've gotten past this didn't do it by volunteering, gratitude or therapy; they got it by *getting theirs.* One thru-hiked the Appalachian Trail; her husband and son sent packages and visited her at different places during her 6-month journey. This changed their dynamic, and since her return they've settled into a new normal which now works for her. Another lost most of her savings building a home with an unscrupulous long-term boyfriend. She put a lawyer on it, resigned from her tech management job, packed a backpack, traveled cheaply and now lives in a second-world country with a local boyfriend who dotes on her. Now she eats what she likes, hasn't been to a gym in years, and is effortlessly below the goal weight that eluded her for decades.
For me, it took a car accident and head injury to find the self-awareness and courage to finalize a dormant divorce from the "great husband" whom various therapists had told me to be grateful for, and to limit contact with "wonderful family" with whom contact left me drained. I've pretty much discarded the string of academic achievements and professional accomplishments that used to define me. Now, earning an above-average living doing something self-taught feels more *me* than anything I left behind. I have specific thoughts about the wonderful man thing, but you'll PM me if you care to hear them.
I don't recommend my option, the bad breakup, going without plumbing for six months, or any specific approach. It sounds like you're already awakened to your need for more, for different, for something.
Specific suggestions are hazardous, but by way of example:
If you're a talented writer/editor/literary critic, what about "getting yours" in that area? You could join WWA, if that's your type of writing.
http://westernwriters.org/membership/
Sure, going to their (or whatever association suits you) conventions would cost time and money and effort. But you're worth it, you'll be the best-dressed person there, and you'll harvest accolades for something you might care about more than what you're wearing. If nothing else, it would be a good time. And plenty of innocent but very satisfying flirting.
If most of your non-work reading/writing time is spent on YLF, that's not feeding an essential part of you. Writing here is for information exchange and social interaction; that's good enough for us non-literary types, but a fashion forum as primary outlet for writing must be pretty unsatisfying for someone who's capable of and needs a lot more.
Writing is just an example; maybe you have other talents where you'd prefer to "get yours." The point is, to get it.