I am a Comcast/Xfinity customer in TX and I am currently paying for 105 Mbps speed. I am not getting these speeds and have been having frequent outages.
The hosts changing are simply the servers speedtest.net uses to check the speed (between your house and their server). They have different locations all around the world for you to test your speed to. You can manually choose the server, or let it automatically select based on ping (which one it can reach faster). Maybe choose the same server each time and you'll get more consistent results, but ultimately this has nothing to do with your internet.
If you're having issues with reliability of your connection, ring up your ISP. Packet loss in the router error logs are common too - so just talk to them and they should be able to send a tech out and work out the problems. But varying speedtest.net results aren't an indication of internet unreliability.