Congratulations on your weight loss. I agree that your next trip is very likely to be better than the last!
I don't typically recommend other unofficial sites, but this
https://allears.net/walt-disney-world/wdw-planning/walt-disney-world-at-large-2/ might alleviate at least some of your concerns.
I agree that site will be helpful to you and I’ve got a couple of other resources to suggest:
The disABILITIES FAQs thread has information about rides with moving walkways, stairs or difficult transfers. That thread is located near the top of the thread list for this board or you can follow the link in my signature. The first post is an index that tells which post has which info.
There are Posts on page 2 about attractions with moving walkways and attractions that may be difficult transfers.
The date for the thread may look old, but the date reflects the date it/each post was originally written and doesn’t show edit dates where they are easy to find.
Pammie Plus Size on YouTube. She has good videos that show an overview of the ride and show the queue, boarding process, ride car and at least part of the ride. At the beginning of each video, she tells her height, weight and clothing size to help viewers get an idea of how they compare to her.
Big Fat Panda on YouTube. His more recent videos are more general, but he has some ride videos that show the entrance, queue and boarding as well as the ride.
Search the Disboards or the internet in general for ‘Pooh sized’. A lot of people use that term for being a larger guest at WDW.