How to think properly in OTB

I've been playing otb recently after playing mostly online games, And i just get wrekt when i play otb. I can't seem to think properly and see the board properly. On online chess i can play just fine, But in otb i just do ridiculous blunders and struggle to visualize. How do i fix this? I get that i just need to play more otb and study, but is there tricks or something? 

I suppose it is primarily due to the 2D pieces online; although you will start visualizing OTB with time as you play more games, you can probably make-do with 3D ones instead for when you play online until you are used to visualizing.

@1

Do you play the same time control over the board as online?
What works in a faster time control does not work in a slower time control.
A slower time control also requires more stamina to stay concentrated a longer time.

That's most likely the case because when i stand up, The board is smaller, or im just taller than the board. I somehow think much more clearly for some reason most likely because it feels like online chess, But i dont think at the same level as i do online. Tho im pretty sure it's just due to nervousness a few otb games should fix this. My big problem is the inability to see the whole board properly and lacking in visualization in otb. Is there like ways so i can fix this or am i just suppose to stand up every game til i get used to it?

I had the reverse problem when they introduced ICC and FICS in the late 1900's.  (I love the sound of that!)  It took quite a while to adapt to the 2D computer screen.

You'll get used to pieces that you can't click on.

I hear it is a problem for some people who learnt chess online in a 2D format and have difficulty visualizing in 3D when playing OTB. I guess it's just a matter of practice.