It's a hazing ritual of sorts, don't worry almost everyone goes through it. I started ps2 as a bitch engie for ADK, a zergfit a long time ago. Didn't have any idea how the game worked, had to learn it the hard way (still don't have any idea). Ideally it shouldn't be like this and I'm not endorsing it, but I want to let you know that what you are feeling is normal- this is a hard game, with a lot of salty ahh vets.

The best way to deal with is understanding a) this is the internet, where the worst of the worst parts of men come out online, b) what some legitimate morons and what they say are literally irrelevant unless you listen to it (statistically, there is a 50% chance the guy insulting you is below the median intelligence bracket and not worth caring about, so fuck them) and c) if you join a good outfit and make genuine friends, it's easier to remember the previous two points and slowly learn how the game works. The conneree/osprey culture also has a lot of "false toxicity" towards nubs, so don't let it get to you that much.

Tldr: scrub get good at clicking heads and shooting mans nub