I am a worrier and a planner. My DH and I have two boys, one of which has special needs that makes traveling more...interesting.

We took our first trip (a quick one, just two days in the parks...MK and EP only) back in 2011. Since then we have gone to WDW every year. It's that....well...magical. I know it sounds super cliche and cheesy, but it's true.
We have encountered some sort of pixie dust on every single one of our trips; when we reminisce, we recall the pixie dust that went with each trip. We have found CMs to be amazing, the weather to be great (we're from the midwest, so we're not hard to please), and we just simply do not tire of the attractions. Even rain in Disney can be fun...just throw on ponchos and enjoy the lower crowds!
Most of our trips have been short (think 3-4 days in the parks) but we love Disney so much, we find we have been adding days to our trips every year. Our first trips only included the quick service meal plan, because our boys were too wiggly to sit for meals and they wanted to get to the rides. However, as our boys have grown, our last couple of trips have included the regular meal plan and we've started really enjoying the TS meals, and now when we reminisce, our boys recall the great meals and servers we've had. WDW is truly a place that can grow with your family. The things my boys loved doing as a 6 and 9 year old are still things they like doing as teenagers, and yet they enjoy doing new and different things too. There aren't many other vacation spots that I can think of that grow with your family like WDW.
WDW is truly a place, especially when you stay onsite, where you can leave everything behind and just be present with your family. My DH had never gone as a kid, and so his first experience was when we took our boys for the first time. DH is as stressed by crowds on trips as our youngest, and yet, somehow we can't imagine not doing Disney. There is something really intangible and magical there. The sights, the smells, and the genuine heart and vision Disney had combine to make trips there amazing.
I understand your worries, as I am someone who worries and tries to anticipate everything so that I'm ready for anything. However, I really forced myself with our last trip in June of 2017, to just be present. To enjoy the little moments, and to just go with the flow more. As a hard core planner, we of course had FPs and meal reservations that I worked on with our TA. We watched every POV everything we could to plan for the new Pandora area that had just opened up before we went last year, and I started packing weeks in advance. However, I worked hard to let my family take the lead once we got there. With a solid touring plan (up early to hit the parks, go back to room in afternoon to swim, return to parks later in the evening) you can really do pretty much everything you want, even with crowds. When we got hot and tired, we bailed out and let ourselves rest, we visited other resorts more than we ever have and really enjoyed checking new places out, and we used transport boats more than ever this trip. Some days, we didn't get up as early as I had planned, and we even skipped a FP or two. And you know what? This was our BEST trip yet!
So, really my only advice to you is to simply be excited about your trip. You're going to WDW! It's such an amazing place! Savor every minute of your trip with loved ones. Have a general plan for the parks each day, but be flexible enough to read your group and make changes when necessary.
I know you'll have a magical trip!!!
