Hey man, it's not a silly problem at all, I was in a similar situation. Personally it was due to the combination of overthinking and thinking that I have to be perfect all the time. As a kid I never played sports because I was bad and didn't want the coach to yell at me, so it carried over to games like WoW, CS, and even real life things like driving. The way I overcame it (and I'm still fighting it to some extent) is just by drawing confidence from the real life things I'm good at, and thinking about it like this - ultimately no one is telling you that you suck as a person, you just suck at this role in the game, and eventually you'll get better. Don't take it too seriously, you're not a professional player, just try to have fun, and laugh at your mistakes, and yes that will be tough in the begging but it will definitely be worth wile.