You've never had to adjust so it is foreign to you. It's not the end of the world. You just need to know what the struggles are so you now how to adjust. Once you are able to recognize the what and the why, you can implement the necessary adjustment.
1. How do the other tables play differently than the Diamond?
2. What part of the game are you struggling with on the other tables vs the Diamond?
It's your state of mind when you are faced with the adversity that is getting in the way of executing like you know how. The thought process cannot be, "I'm fucked. This table doesn't play anywhere near my table at home. No way I can play on this." It has to be, "This table plays differently in these ways....I need to adjust X Y Z to play my best game."
I was faced with a very similar circumstance recently. I have a Gold Crown I that I restored, had new rubber installed (Diamond Black), had the subrails extended and the corners cut to 4.125" (141*) and the sides to 4.875" (103*). The table plays a touch on the fast side and the pockets are tough but fair. I've played exclusively on Gold Crowns for the better part of a few years but recently joined my buddy's BCA League. They play at a local pool hall on first generation (Pro Billiard Tour) Red Label Diamonds. They are much slower than my table, pockets are 4.5" and 5" but they have a much deeper shelf than I'm accustomed to. When I started the league I was rated a 623 Fargo. My first week was bad and I really didn't start to adjust to the tables util the 3rd week. My Fargo dropped to 598 but is now back up to 613 and I hope to get it back to where it was or higher by the end of the session. I did not play on those Diamonds except for league night and continued to practice on my table. The table was irrelevant as I knew what I needed to work on during practice to play like I can on the Diamonds and focused on that. Because the Diamonds are slower, if takes a little more stroke (not much) and a little more english to move the ball around the table. The tables are no longer an issue. They never really were an issue. It just took me a little longer than it should have to adjust.