Shun[What tools have you used to test things? It's been a while since I've tested network connections with traceroutes but running a tool like this throughout a day could show interesting things: https://www.pingplotter.com/download.html
More simply, if you're noticing severe lag at night, run a ping test to anywhere in command prompt with ping <server> /t which will run the ping continuously. Make a friend in your dorm and try that on their computer while you're seeing lag. If they see it too, it's campus network related, not you. You could also try running pings from campus computers.
dollarlayerI know you mentioned CMD pinging not working and being blocked, but you could try other methods as well or use a VPN to do the pings.
I would try running a free program called WinMTR. It basically acts like a continuous ping tool, and can be set to basically do 100's or thousands of trace routes. You can pick an IP such as a TF2 server IP that you game on sometimes. It will tell you the average latency of each hop, including the hopes on your local network. Then you can maybe identify if there are any specific hops that seem to be problematic, and trouble shoot the issue further.
I'm willing to try more, just let me know. Would a VPN allow me to run pingplotter (or WinMTR)? My only fear with any VPN usage for testing is the inevitable "You clearly aren't having any issues as we discussed earlier, but the VPN you are using is now causing your lag and instability"
edit: any traceroutes I run have to be run through their website.