It's all about expectations, I think. There is so much advice (both great and some not-so-great) on this site and others giving strategies to get the "best" ADR and not-to-be-missed fastpass. It makes you think that if you don't get everything you want 11, 7, 6, and 2 months in advance, your vacation will be a sad disaster. That's such a crock, but I fall for it too.
We do go often, and I've planned trips for groups of 6 to 20 and more. I enjoy the planning, so I do it. And it is scary when Disney changes something because I'm not sure how it will impact my own "strategies". So I do experience the same stress that OP has gone through, and to an extent, the same frustrations.
With the advantage of having gone several times, I can tell you with full confidence that the ADRs you didn't get and the rides you didn't ride and the shows you didn't see will not be what you remember about the trip unless you want them to be. Instead, you'll remember how exciting it was to see that WDW sign above the road as you arrived, the courtesy and friendliness that surrounds you and makes you want to be courteous and friendly too. The look on that young one's face when they first see the castle, the pictures you took that were completely goofy - but everyone was smiling, and the sweet togetherness of sharing a sit down meal (at your third choice restaurant) when everyone is pleasantly (ok, that may be a little sarcastic) exhausted from walking 8 miles so far today.
You'll also remember (and hopefully be able to smile about) the complete meltdown the toddler had at Animal Kingdom, the blisters on the back of your heels from those new shoes, the wasp sting that put your 10-year-old out of commission for the whole day at Typhoon Lagoon, having to call your pediatrician to call in an Rx for a rescue inhaler to the pharmacy in Orlando because you forgot to pack it (mommy guilt still alive and well), having the construction crew run into your rental car in the parking lot, and oh yeah, the snake in the room.
All these things have happened on our
Disney vacations - and yet, what we remember is the time together, enjoying ourselves as a family.
OP, what I hope for you is that in the end, whether you decide to visit WDW again or not, is that you decide to place the most importance on enjoying the time with your family while you are there. All that advance planning doesn't sound like your cup of tea - and that's completely okay. But now that you've done it, I hope you are able to relax once you get there and enjoy the fruits of your labors. Have a fabulous vacation!