Chad, "go ER" and shit like that came from the modern incel community. The term incel has been around for like nearly 30 years now, but the incel culture as we know it today didn't really start until about maybe 2014? That is definitely when the term "Go ER" started since that is when the shootings happened.
Modern incel culture came from the PUA culture, when guys started realizing that PUA was a scam. I was pretty deep into PUA and don't think it was a scam. Well, it is today, but PUA was pretty legit until like ten years ago or so. PUA only really works in a pre-tinder world.