Connectivity issues across all devices on LAN

I'm using a NETGEAR C6300 Modem/router through Comcast, and last night seemingly out of nowhere Netflix videos would error out (or load indefinitely).
All today webpages either don't load, or don't fully load. For example Google sometimes comes right up, and searches sometimes display immediately, but most sites I visit from the results come back with "ERR_CONNECTION_RESET," "ERR_CONNECTION_CLOSED," or "DNS" errors.
Some websites kind of load, for example facebook comes up with all the usual business, but only loads one or two stories, and scrolling ends abruptly and i get a "loading" graphic that never comes in. Netflix I can browse my stuff, but I try to view any movies/shows it loads indefinitely before giving me one of a dozen different error codes that all tell me the same thing.
I've power cycled the modem/router a few times, and factory reset it, but neither have worked. I've flushed the DNS but that didn't work. And I've run a "Tracert" through the cmd on a few different sites, netflix seems to bounce back a LOT of request time-outs, but facebook does not. And I've run "netsh int ip reset resetlog.txt " and that didn't work either.
I'm having these issues hard wired to the modem/router at my desktop, through WiFi on my laptop and phone, and netflix flips out on my PS3 as well, which is hardwired.
Windows troubleshooter finds no issues (shocking), and every device claims to have internet. I'm at my wits end and have combed through the web, but everyone who claims to have the same solutions don't have answers that work, and trying to get webpages to load well enough to get info is a disaster. Despite speed tests reading 50-100Mbps download speeds, some sites take a good 5-10 minutes to load if they don't error out entirely. Any help would be appreciated.