I'm good at chess in person but not online?

If I'm playing against a person I know, I always do great, even if they're better at chess than me. Meanwhile, if I play with people on chess.com, I almost always lose. On one game, I resigned, but when I looked at my game review, it says I had on overall better opening than my opponent. 

Am I just psyching myself out, and is there a way I can fix this?

I don’t understand how that’s possible

if you’re not good online, you’re not good at chess

I'm the opposite. It happens

Your account seems to be very new. And because you haven’t played so many games, your rating is unstable. Once you played enough, your rating will be more precise and will pair you with opponents equal your strength.

In my case, I am mainly an online player. Sometimes I play otb very well too… And sometimes not.

Play more, maybe you get used to the 2D board. Otherwise you can try the 3D Pieces-Design (The very last option in the list).

#5 I am also better online, probably because arrows, premoves, and clock doesn't have to be pressed