Packet loss and high ping in every online video game

Hi there!  I've been hesitant to post on here, as I'm not quite if I'll find any answers, but here it goes:

 

My issues started back in October.  Towards the end of the month, I attempted to start streaming on Twitch, but was met with constant frame drops.  Over the course of November, I did my due dilligence.  Replaced my network card, tweaked MULTIPLE PC settings, reformatted and reinstalled my PC, changed coaxial cables, Ethernet cables, and the splitter.  Nothing has worked.  I've had multiple technicians come out, but none really wanted to help.  One guy even came to my home, did one test, said it looked good, and left.  I have the default XB6 modem, and it's been replaced four times.  One time to see if it fixed the initial issues, and the other two times because I received the Arris version of the modem, which is apparently awful, as it constantly restarted.

 

I've had techs out to check the wires and the node around my street, but nothing seems to work.  The only tech that actually wanted to help wasn't able to come back, as my mother was ill at the time.  He had the idea that maybe there's a faulty splitter somewhere in my home, or that the RG59 coaxial cables around the house are degrading my signal.  He also stated that if that didn't work, then maybe it was due to some old wiring around the house.

 

Unfortunately, I won't know, at least not at this moment, as I'm living in a townhouse, and I'm completely unsure how to go about replacing old wiring.

 

The reason I'm posting here is because it's February, almost March, and I'm at my wit's end.  Is there any other possible way to identify the issues?  I have gigabit currently, and the thought I had was maybe because of old wiring, the frequency wasn't being transmitted correctly, so maybe downgrading could help?  I honestly don't know anymore.  I would post pictures of my downstream and upstream, but I'm not sure how.  On top of that, I was told that the levels of everything looked to be normal, so again, I don't know.

 

Is there anyone who can help or give me some ideas?  Could downgrading possibly help?