I feel so week even though he is wrong I can't...

You have to know that we are all human and subject to error, as we are not angels and all human beings make mistakes. But a mistake about a mistake is what you should think about. If the mistake is simple and can be bypassed, give it another opportunity. But if the mistake is frequent and large, and you tried to fix it but did not find any result, then you have to stop and think again about this relationship.