My most recent one is at 3.4MB.
Apparently, a lot of people have this issue once they've been playing a save for awhile -- it seems to be the ones at 30+ hours that start becoming a problem. The problem is, of course, at 30+ hours is when the game is the most fun. But for now, as soon as the sim I have at level 9 of her career levels to 10, I'll just start a new one. I want to try rotational game play anyway, but hopefully that doesn't make things worse.
Thank you for your time on this. I just don't think there's a solution right now. I've done all the suggestions, and the only thing that changed the load times at all was putting Origin off line -- and that was negligible. The only iffy part of my system is the graphics card, but even that just is a small bit below the recommended system (650m GTX as opposed to 650 GTX) which is well above the minimum requirement.
Edit: Right now I'm hoping enough EA is aware that many people are having this problem and look for a fix for it.