We are looking at specific issues to apple routers.. what apple router do you have? We cannot answer general queries on why internet is slow.. unless it is being caused by apple router.
Have you plugged your MBP into the modem by ethernet.. and done a speed test.. nothing else in the house turned on. Wireless in the MBP off. What speed do you get.. ??
If it is still slow you have to work it out with Verizon .. get them to send a technician who can check the speed.