Internet keeps dropping - at my wits end

Like other users here I'm having the ol' "internet keeps dropping" problem.

Multiple chats with Xfinity have led nowhere beyond resetting the signal (I do not know what that means). They did persuade me to upgrade my plan, which I was told would lead to better speeds.

Now here we are. I got knocked off my Zoom classroom today (I'm the teacher, it's very embarassing). It happened 3 days ago too. My husband got knocked off his Zoom class. Throughout the day the connection goes in and out. It seems the system can't handle two computers on Zoom at the same time. There's only two of us and no one is gaming or streaming at that time or even using the phone on wifi. It's just Zoom. The internet connection will also die randomly, even if there's no streaming or Zoom going on, just me and my phone. It's not reliable.

Internet will die for about 30 seconds and then it's a struggle to reconnect. Usually I have to turn off the wifi on my computer, then turn it back on, and after a couple of rounds of this, it comes back on. Same thing on iPhone. I have to turn the wifi on and off a lot.

Speed tests are all over the place. Within the span of two hours today, using the same device in the same location,  I got: 50mbps; 22mpbs; 16mbps; 20 mbps. This is with the Xfinity test. Another speed test, not Xfinity, gave me 1.8mbps.

I'm not a technician and know nothing about wiring, modem reports, nothing like that. I just want this to work consistently. Looks like that's too much to ask from Comcast. Really wish there were other ISPs in my area, but Comcast is the only thing I can get here.