Hi and sorry you're having a difficult time with your son's tantrums and other behaviors. Since he's resembling your brothers behavior, you may need to consult your sons doctor if other methods don't work. I'm a parent of 2 girls so I'll try to offer suggestions. First off its normal for kids this age to have tantrums and for them to assert themselves...but there's a limit of course.

This is what helps with my girls tantrums - I would let them go through the tantrum and not pay attention to the behavior...unless I was in a store and in that case I would take them home. If he's hurting you, its best to try to restrain him calmly so he doesn't hurt you. What you don't want to do is, try not to negotiate or deal with him when he's in meltdown - it falls on deaf ears. Have you noticed if his tantrums happen when he's bored, tired or hungry? What you don't want to do is give in when he's having the tantrum - being consistent is important. Having a routine at home and activities to keep him busy also helps.