Your O attacks you?

While I can't help with Garlic, (I hope he's ok!) I do have tons of experience with Oscars. If you want to give him something else to attack besides your hand, try this:

Take a ping pong ball and punch a hole in it to where it will fill up with a little water. Throw it in the tank then grab Garlic when your O is chasing the ball. I have an O named George who attacks his ball when I'm cleaning his tank. If he's in a decent mood, we'll actually play ball for a minute or two. Anyway, it keeps him away from me and gives him something to do when he's bored...which is usually at around 4:00am.