How do I remove a spell "stuck" on my hand in Skyrim?

The spell "Lesser Ward" is stuck on my right hand in Skyrim. I can no longer replace it with another spell by using the GUI, and I can't unequip it either. Using the "favorites" hotkey, I can equip both hands to a spell and then equip another to my left hand to get a wanted spell on my right, but this is a bit cumbersome. Since I'm a Khajiit mage, I like to have a spell in my left hand and my right hand free for attacking.

If I try to use the console to remove the spell, my right hand simply doesn't do anything. I then can't attack, but I can't use the offending ward either.

This problem persists through saves - if I load a save from before the problem, I still have the spell in my right hand.

I've found a solution! After I created a character ("Test Orc", the ugliest mug known to man) to see if the glitch persisted to new characters, I loaded an old save from before the problem occurred. Lo and behold, the glitch was gone! It's probably because of some cache nonsense (like Alice Rees said in the comments).