Games : How to get un-psyched from something

I am here to ask about advice on how to get un-psyched for the skill bracket that I am currently in for Dota 2. Do not get this confused, I am here to ask about how to get un-psyched, I am not actually asking a question about Dota 2 I just want to know how to stay calm even though I feel like I am a pro because I am in a high skill bracket.

Basically my goal was to reach this bracket in the long run.. But now that I am here I feel over confident and that I know everything about the game and now looking back into the games I played like a retard. Yes okay, I made really stupid mistakes and whatnot but I feel like I wouldn't have made those mistakes if I wasn't so psyched up about being in a tier which I feel is for people who have extensive knowledge about the game.

And now that I reached my goal (as I explained before) I am really over confident and I am asking how can I get rid of this? Next time, I will try and listen to music as I play, play heroes I am comfortable with etc. but is there anything else that I should try?

Thank you.