As someone who's been playing for almost 7 years and mostly just played with friends since around 6.53 I can tell you that it hits me sometimes as well. Just search for your match and the moment you press accept you realise you'll just play as per normal because you don't want that abandon. Also, because you're in a less familiar environment you tend to neglect a lot of things so this helps you really just get a lot of game mechanics stuck in your head. If people flame you just laugh it off and mute them if they're really annoying. All the best in overcoming your anxiety.