There is not enough information in your post for a proper clinical assessment. However, there are some general things you should consider.
- "Nipping" can be caused by excessive arousal or attention-seeking. Unless you're under-playing it, nipping shouldn't be classified as "attacking you."
- Scolding your dog may sound like barking and amp up the puppy, or it may make him fearful of you. Either way, this is likely to lead to more, not less, aggression or guarding.
- Your dog may be resource-guarding your wife. If so, this is a serious behavioral issue that requires professional intervention.
In the general case, rewarding your dog for low-energy behavior is probably your best bet. Spend some time in the evenings rewarding him with treats for sits or downs, give him a chew toy or raw meaty bone to keep him occupied, or anything else that is acceptable to your family and a relatively sedate activity.
If your dog behaves inappropriately, a good look-away will signal your displeasure better than a verbal scolding. While it may increase attention-seeking behavior in the short term due to extinction burst, this kind of signal should be instinctively interpreted as a calming signal and may stop the unwanted behaviors more quickly than you expect.