Slow page loads, please help

Hi,

I posted about this yesterday and heard nothing at all.  I'm hoping someone can help me.  My browsing is unbearably slow despite having a good speedtest.  I've called a few times, and nothing helps.  A power cycle will help for a short period of time, but then back to 10-15 second page loads, and sometimes it will even time out all together.  I read a few other posts with this same issue.  Some said it was a DNS issue, others claimed they got a new, albeit older model modem, and that it fixed the problem.  I'm getting really tired of paying for internet that doesn't work a lot of the time, and being told everything is fine.  10 second page loads is not what I expect with a 300 mpbs up and down speedtest.  Please help.

Hopefully someone from ATT will reply? 

Thanks!