Verbal abuse is not to build character, it is to break character. Think army drill sergeant. Why do drill sergeants act the way they do?
First break you down and then build you up to be a soldier.
To some extent this goes for martial arts to.
In Aikido I think this is very much out of place.
Think deeply about why you would want stay with this teacher. Is he that good? Or is the dojo conveniently 'there'? If you cannot find a (very) good reason to stay, leave immediately.
I could not agree more. However in some sense you have to take responsibilty too, remember you can choose to stay or choose to go, but whatever you do choose be happy about it. Nobody and I mean nobody should make anybody feel worthless. If this is the case what worth is it staying with this teacher, in fact I would hardly call this a teacher, it`s a bully!