Why do I log in to this so often?

Illustration 1: you have to wait for the message from the sim telling you where your avatar is... until then, the viewer just pretends you're at 10, 10, 10

Illustration 2: in this picture you're waiting for the downloads of clothing, terrain, and prims

It never loads, though.

Maybe a problem on your end with your network.

Try unplugging/resetting your router.

I have reset my router and stuff, and my internet connection seems pretty stable, although it is a possibility since I use a wireless connection and the router is a bit of a distance. Here's another thing: clearing the cache doesn't always work, but deleting the cache folder in application settings seems to. But no matter what I do, it always eventually comes back.

Wireless can and will be an issue depending on the card ... I can run it but I have an older lap top that has to be hard wired or I am a cloud!

get 2 wireless cards one will send one will receive

Here's another thing: I can log in with my alt just fine, but my main one that's three years old and has a hefty inventory often hangs up on the "connecting to region" and logs me in to the screenshots above. Is nobody else having this problem?

Do you live underwater?

Have you tried logging in to a different region, or detaching all attachments to see if that helps? There have been cases through the years where something was corrupted in inventory and stopped login - that's rare, though.

I saw a post once recommending you add -purge -noinvlib -safe -nosound -noaudio -nofmod -ignorepixeldepth to the shortcut target, then see if you can log in and remove attachments and if that works try relogging normally.