Internet Dropping Constantly

My internet is constantly dropping. The traceroute I performed showed three of the Comcast servers are either not responding or extremely slow. My modem is telling me that there are upstream issues. Why can't we just have good internet? 

Here is what my modem is saying:

• UCD invalid or channel unusable
• SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
• Started Unicast Maintenance Ranging - No Response received - T3 time-out

From what I understand, these are all upstream issues. I will be buying a new modem soon, the Netgear Nighthawk CM3000. I don't know if this can solve the upstream issue, but I believe it may help. 

Currently, I have the Arris SB33, which has been a fantastic modem for the past couple of years. 

*Rant*

What is up with this stupid chatbot Xfinity? It told me that my cable is probably bad. It was not. I built and tested my own cables, and yes, I replaced that one with a known good one. No resolution. I'm sure you intended this bot to drive people away from talking to your help desk, which it does. What a shameful practice. We need services that work and individuals who care to help. With other services moving up, I thought y'all would make it a point to care for the people lining your pockets instead of playing dumb.

--UPDATE--

I got the Netgear CM2500 as it was $50 less and supported my speeds. After troubleshooting with the techs, I am now up and running better than before. I don't know if this was a configuration thing or if I just needed a new modem. I did have some random inactive equipment on my account for some reason; I wonder if this was part of the cause.