Artists dont group together after i change their names

Ever since i updated my itunes, when i try to add/change a name of an artist to put them in a section it doesnt work. For instance when i upload my garage band tracks to itunes the artist is under my computer name and thats different than my artist name, so i choose "get info" on the track, change it to my artist name, and it usually groups all my songs together. But now it does not do that, i now have my artist name twice in my library. Not altogether. I even downloaded a Taylor Swift remix and i couldn't get it into my Taylor Swift library. I changed all the info to get it to her name but it just adds another column that says "Taylor Swift"

this is very irritating.