Your line has great stats so the problem is not the DSL connection itself but somewhere else within the Verizon network or your computer is using the network and you are not aware of it. That is unlikely since you have tried different computers. If you torrent be sure that is disabled. When you run speed tests be sure nothing else on your computer is using the Internet.
Next step to do do a traceroute (tracert in Windows) to stable sites like this one. Do that in good times and bad. Latency should slowly increase with hop count and distance, sudden unexplained increase typically indicates congestion at that or the previous hop. Given your speed should be seeing about 20ms to the first Verizon edge router.
What you are seeing is typical of congestion within the ISP network, most likely backhaul out of the DSLAM that supports your line.
Good luck trying to get it upgraded.
What happened in response to your previous thread about this?
»Please help me to get moved to a less congestion DSLAM.