You know, having read through your entry...
In all honesty, I would prepare for the possibility that you may deal with postponed grief within a couple of months or even a year from now. While I never made big $$ nor did I have a stellar law degree, I spent most of my working life and/or volunteer time with high impact, high variety, high stakes jobs (namely, social work and corrections). I spent the first year at home destressing from all those years of living on the edge in just about every way possible (financially, physical danger, dealing with other people's emotional breakdowns/explosions). But then, insidiously, I started to miss that stimulation. I think for some people they can fill that by taking a million mommy and me courses, but it didn't work for me (plus since I had 3 kids in 17 months, didn't have the $$ or energy to do that for all of them either). I was so used to being a go-go-er, that it took some time that was even more difficult than I anticipated to learn how to be a be-er. So much of dealing with a bunch of little kids is be-ing and letting them be, instead of cramming a zillion activities down their throats so that you can satisify a high drive to "do something." (because to be blunt probably LLL...unless you undergo the training to be a leader..and other mommy orgs are generally NOT going to have the same go- or do-er satisfaction as breaking up a fight between inmates or fast-talking your client into a shelter at the 11th hour. At least they didn't for me--more power to people who did find that level of satisifaction!)
All I'm trying to say is that it is normal after the SAHM honeymoon period is over to have a certain amount of "buyers regret" or to feel like you're a horrible mom because you really don't find as much intellectual stimulation out of the under-three crowd as "everyone else" seems to be having. It's okay. Hopefully you have more of a sense of humor than I did initially, but if you don't don't worry, you'll develop one. ;)
I love SAHing. I do miss my ladies though. I miss hanging out with street folk. Sometimes I feel that the SAHM community is very hostile towards anyone talking about how they enjoyed aspects of their former job(s). (And for me personally, there is also the factor of me being a SAHM in suburbia where people react in stupidly stereotypical ways when the find out that I had regular contact with streetwalkers and mentally ill people for a long time, so often it's a double whammy for me if I admit that sometimes I do miss my old jobs and volunteer gigs!). OTOH, it's been nice to meet and socialize with a suprisingly diverse group of folks as a SAHM that I wouldn't have otherwise.
I have no regrets about SAHMing. I just try to remind new SAHMs that if you wonder every now and then "OMG what have I done" or "Wow, this playdate is freakin' boring," or "My god, if I have to play barbies <or insert more appropriate PC toy here> one more time today I'm going to pop their heads off and throw them across the room," it's not a sign that you're in the wrong place; almost everyone has "what if I did this different" daydreams, and it's just a reminder to love on yourself a bit and to take a deep breath and return to the moment you're in.
Oh, and BTW...I've had my SAH gig for almost 10 years now, still having a great time. :)