iTunes issues with album artwork

My iTunes seems to be having quite a few problems handling album artwork. I don't know if they're related at all but they both started almost right after last time I updated iTunes and have been driving me crazy ever since. Since that fateful update, iTunes seems to pick and choose which album art it's going to download from the iTunes store. Making sure that all the song info matches the album's info as shown in the store seems to make no difference. When I hit 'Get Album Artwork' the status bar in the play window will blink super quick like it downloaded it but then it never shows up. This doesn't happen with every song but it seems to happen most with newer releases. I can never get the artwork for something released this year. Sure, I can pull up the artwork by doing a Google search and paste it in manually but it's frustrating if I'm adding a few single songs and I have to look up the artwork for all of them when that's supposed to be a key feature of iTunes. Is this just a bug in iTunes that Apple might fix in a later update or is there something I can do to correct it?

Which brings us to problem number two. Sometimes when I connect my 5th gen iPod Touch to iTunes it erases all my artwork. The first time I tried the whole deleting the cache file thing. I don't know if it actually worked because I still had to delete my music library from my iPod and put it all back on again. I've had to reload over 5000 songs back onto it 4 times in the past few months. And it takes a really long time to do that. I know I've got a pretty huge library but the whole reason I paid $300 for an mp3 player is for the amount of storage and the easy use and clean interface of iTunes. I love this thing, it's got my whole life on it, but I'm starting to feel the urge to chuck it out the nearest window. When it just happened again I checked the cache file but it was still empty from the last time I had this problem a few weeks ago. I'm going to have to dump and reload the entire thing all over again which will probably fix the problem but how long until it happens again? Does anyone know why the heck this keeps happening? Is there a real permanent fix for this? Judging from the discussions here this is a common problem so why hasn't Apple fixed this yet? Or are they just too busy making watches now?

For reference I've got a Dell Inspiron 545 (64-bit), Windows 7, iTunes 12.1, and ios 8.3 on my Touch. Let me know if any more info is needed.