Do you feel intimidated by higher rated players? I beat this 1570 rated player (me being 1170), but the thing is that i had his rating covered by a youtube pop-up window so I didn't know he's higher rated until i finished the game. I feel like if I knew, it would have made me perform worse due to pressure. What's your thoughts of that? I think that besides good moves, there a psychological side to chess. 

If you are wondering here is a link to the game: https://lichess.org/qlnj6aMS
It really matters whether you are talking about a simple blitz game, or an OTB (over-the-board) tournament game. In blitz, it really is for fun, so you should just do precisely that, and have fun. Do not worry about someone's rating. If you are really into chess, you will play so many blitz games, and you will win some, and you will lose a lot too. Some wins will be great games, and some losses will be horribly pathetic losses. Just move on to the next game. I cannot even imagine the number of losses I have had in my life, but they all combined to make me a reasonably strong player.

Now, a tournament game is another thing, so I can understand someone getting nervous; but you really do not want to think that way if you can help it. I certainly know that if I got a chance to play Magnus Carlsen, I know logically that I will likely lose, but at the same time, I am not at all afraid of him (really). What is the worst that can happen: The predicted result? Big deal. Even that game, I would enjoy.

That reminds me of one other related thing that I just do not understand: In 40 years of playing tournaments, and following chess closely, I have seen a lot of weak players take draws against even world champions in simultaneous exhibitions. Sure, take a draw if it is really a dead draw, but otherwise, how many times are you going to get to play someone that strong, or even an IM or weaker GM? You should play that out, and enjoy the experience, even if you lose.

Back to the subject: You just want to take your time (within reason within any time control), and play good moves. You may not play the best moves every move, but I highly recommend not being one of those people, who constantly gets into time trouble. Funny, I feel like bad clock management, and trying to play too good a move too often is what is hurting Kasparov in the exhibition Chess 960 match he is playing against Caruana in St. Louis. He should just play moves that are good, and do not lose, and hope Caruana makes a mistake first.

Lastly, confession time: For at least the first two years I played tournaments WAY back when, I literally threw up before virtually every game. It was not because of being afraid, but just general nerves; so while I did not worry about someone's rating, I do understand your potential nervousness. I would just try to put it behind you, especially since blitz means nothing. :)

I went a little beyond the scope of the question, but hopefully, the practical advice will help someone.

ONE LAST PIECE OF ADVICE: In a tournament game, NEVER treat a lower-rated player with contempt. ALWAYS play them like you would play a Master. When you do that, you get too sure of yourself, and can make mistakes. I had a period of 7 years that I did not lose a tournament game to anyone below 2100, and I believe that part of it is not taking for granted that I would win.