I tried to answer your first letter - but perhaps my computer didn't send what I had written. First of all, you're not crazy. Fact is, you're a good mother trying to sort out your son's behavior. And that is not always easy. But regardless of the event - you have a responsibility for recognizing unacceptable behavior.
Feelings are real - but sometimes behavior needs to redirected.
I think you said sometimes there is none. Then if he acts inappropriately, after the behavior has resolved - talk about what happened. Talk about how he might redirect that rage - use words, not fists. Offer inanimate objects to hit or bite if he has to have an outlet. Praise him for good behavior - offer stickers or gold stars.