how do I overcome a plateau
You have done fantastic!! Are those last eight pounds that important? If so I would advise a goal of a pound a week. That means decreasing calories by 500 a day. Track everything you are eating and figure out where you can get rid of those calories. That way you will have a goal that you will be able to meet without a lot of pressure on yourself.
Tracking calories now will give you a baseline to stay in maintenance.
Real life begins where your comfort zone ends