For me. I feel like it's fueled by anxiety 80%. When I'm playing online with my friends in comfortable situation I bearly stutter. Hell, I even talk shit fluently lol but when I'm asked a question where I'm put on the spot and or eyes are on me I FREEZE. Making friends is weird for me. Sometimes people do give me looks like dam he's awkward but eventually I warm up to people and start speaking and I'm good. Granted, not everyone has to be your friend. But those who do end up being your friends are true blessings.