Connection cycling

I'm hoping someone here can help. 

For months now, I've had an issue where my internet will go down multiple times a day. For instance, right now I'm sitting in my living room watching my router cycle through all the lights. The connection will last anywhere from 1 to 5 minutes and then drop again. When this happens it will do it a few times to multiple times over an hour or two. Eventually, I just give up and leave, or turn everything off.

I've worked in tech support before so I know the basics of power cycling my device, however it's clearly not the device as this is the third modem I have had because they keep replacing them. (Probably because they have no idea what else to do.) I've checked outage maps, reset my device, checked to make sure the cables are attached appropriately, and I just have no idea what to do anymore.

I've spent literally hours on the phone with support having them go through the same things with me only to tell me that it's working at the end and then hang up because I don't know what else to do. I've spent hours troubleshooting with the Xfinity system, and it just tells me that my device is offline and then I have to go through all of the steps there only to have it eventually work again at some point, or not.

I've had tickets filed only for tech support to call me back and say that they fixed the issue but when I asked them what the issue was they say oh we didn't find anything but it's working now so you should be fine. It's beyond frustrating. I've had two texts out at my home recently that have pulled me away from work, and the only resolution was to change the router.

I believe the issues started after a county contractor's truck unloading a backhoe rripped the cable from my home. When that was reattached, they did nothing to check the cable and I have asked repeatedly for the cable from the pole to my house to be checked and replaced, but the two times that people have come out they say that there is nothing wrong with it because their signal tests that they do at the time says that everything is fine. But of course they're never here when I'm having issues so I don't necessarily trust the signal tests.

Over the last hour it has cycled no fewer than 20 times. 

I will get no signal at all, and then it will say connected but no internet access, and then other times it will say cannot connect due to security settings. But I disconnect and try to reconnect again and then it goes through just fine.

I am hopeful that someone here may have experienced the same thing or have any insight whatsoever as to what is causing my problem and how I can receive help. It is impossible to do work of any kind or watch a show without interruptions. I'm beyond frustrated and no one seems to take me seriously.