Your speeds are dependent on what your bandwidth is from your internet provider.
You could also do a factory reset on your router. You can find out how to do that in the manual, or follow the 30-30-30 method:
1. when the unit is powered on, hold down its reset button for 30 seconds (reset button is a small hole in back of router, use a pin or unbent paper clip to press it in)
2. while still holding down the reset button, unplug the router from power and hold for an additional 30 seconds
3. still holding down the reset button, turn on power to the router again and hold for 30 more seconds
If you also have a modem provided by your internet service, you may want to reset it also.