300 mb internet with super slow page loads

I have att Fiber 300 and it is running as slow as dial up on page loads.  Speed tests show 395 down and 359 up, but this is not translated to page loads. 

I have reset my modem numerous times, I have hardwired and wifi connections that all will freeze/slow down.  After reset it works for a few hours then starts having the hiccups again.  

I have checked the forums and the only true solution is to replace the modem.  I currently have bgw210-700 with software version 1.10.9. How do I go about doing this/or updating the software on mine to fix this issue

I never had these issues with Comcast/xfinity 100