Are you meant to hit your horse if it throws off?

No, you should never hit a horse if it throws you off. Hitting a horse will only make it more likely to throw you off again, and it can also damage the horse's trust and confidence in you. If a horse throws you off, it is important to stay calm and try to figure out what caused the horse to react in this way. Once you have figured out the cause, you can work on training the horse to avoid this behavior in the future.