A.R.
Consistency is the first thing you need to work on. 8 years old is still very young, so some tenderness is also in order. Sending him off to daycare so you don't have to deal is probably not the best approach. Parenting can be very frustrating, but it is at the most trying times that they need you the most. Children don't misbehave to be mean, they are usually trying to tell you something. Try to get him to tell you why he is behaving this way. Also, make sure he knows that the behavior is unacceptable and set boundaries. Some good consequences would be taking away a toy or a privilege(video games etc) and be sure to make the consequence immediate for the best effect. Definitely need to do your best not to give in to get him to stop whining. Encourage him, by giving him examples, how to express himself appropriately. Like " instead of calling mommy names you could say, I feel frustrated because..." be sure he has had a consequence for the bad behavior, then follow with the advice. You need to have patience and, if possible, a united front with his father. Ask his dad to put aside the blame and help address the behavior together. Everyone will be happier in the long run. Best of luck!
A.