You cannot break your funny bone by hitting it.
When you hit your funny bone you're actually not hitting a bone at all and actually you're hitting a nerve which causes the funny feeling and is why we call it a funny bone.
Hitting your funny bone causes you to hit your nerve which is called the ulnar nerve against the hard surface of the humerus bone which runs from your shoulder to your elbow.
Hitting your funny bone should cause no damage and the weird feeling should go away within a few seconds.
I've hit my funny bone several times as a kid and never had any issues.
You're not actually hitting a bone and so you cannot break that bone by hitting your funny bone.