CM1000 modem comcast gigabit - slow speed

I've been going through the same thing.  I had comast tell me that i needed a tech to come out. Tech came out, tested lines, couldn't find a problem.  He did nothing and left with my internet still at 200Mbps even though I've been paying for Gigabit. He called a field lineman out to check the line coming to the property. That guy came same day and ran tests.  Told me all is good, no noise in line - nothing he could do.  He suggested I called to make sure provisioning was correct.  I'd done this already but now that I'd had 2 techs come tell me the hardware was fine, I made the call.  I got to Tech 2 support (wirelesss gateway team) and was told they could see massive packet loss and the gentleman didn't understand how the techs didn't see the noise.  So he scheduled another tech for the following morning.  New tech comes and tells me the guys on the phone don't know what they're talking about and all his tests were fine.  Told me they just say packet loss to make customers feel good and really they can't tell that from the phone, nor noise in the lines.  He did, however replace all the coax cabling and schedule a team to run a new underground line from the street to the house, setting up a temporary above ground run for now with flags marking the wire.  Guess what! Still get max of 200Mbps.  If I play games on my PC and stream to Twitch, internet slows to a crawl.  Under 1Mbps down and up.  It's repeatable and consistently awful.  I bought a gigabit ethernet switch but it wont power my Eero pro router and computer via direct connection. Something about needing multiple public IP addresses.  Don't think it would work anyways since direct Cat6 connection from the CM1000 to my PC does the same thing.  200Mbps.  I get about 700Mpbs for 5 minutes after i restart, sometimes, but it quickly falls to 200Mbps and hangs there.  As soon as I turn a game a twitch stream on, im in unusable territory.  Do I just throw in the white flag and get a Xfinity gateway?