"You can’t open the application “iTunes” because it is being updated." error message (macOS high Sierra 10.13.6)

when I try to open iTunes it gives me the error message "You can’t open the application “iTunes” because it is being updated." this began after it said iTunes needed to update to be able to update an iPhone I was attempting to set up via my MacBook Pro (2010). I've tried multiple things, downloading and attempting to re-install the latest version of iTunes for my model- I got the error message that said I already have that version of iTunes installed. I also tried restarting my MacBook and holding the left shift key while opening iTunes, and that didn't work either- I still received the error message stating that iTunes is being updated.

any answers or suggestions are greatly appreciated, thx:)