can't connect to the internet with any stability

Hello! I hope someone can help. The tech support line is having technical difficulties (very encouraging LOL)

Here's the problem: I cannot seem to maintain a connection w/ the internet.  I have had to resort to using my hotspot to write this message and do any work.  i am at a loss!  I can restart the gateway and that helps but only for a short while.  The message I get says can't find DNS 

Thanks!