All right nobody ever does this on a support thread so 
This could specifically be an external problem.
You should do all of the local stuff, this can be a performance issue - if you can stand still for a couple of minutes (5+) and still nothing loads, you might just need to hang back for a minute. It turns out that this can also be caused by problems at amazon.
- Able to connect to worlds/log in.
- Able to move around worlds, maybe even re-open recently used portals.
- Only a few chunks of (recently cached) landscape available.
- Also able to load non landscape-related data. (in my case I could still load signs but not blocks).
- Not experiencing other performance related issues. I see you don’t have any “unplayable connection” warning going on either.
In my case it was tracked down to an incorrectly configured server at amazon that wasn’t properly routing chunk data requests, or something like that. If it’s something like that, it should be transient, but that could mean anything from a couple hours to a few days depending on what actually happened.
If you want a link I can dig up the troubleshooting thread. I’m moving this to support, good luck.