Ice blue zebra cichlid spinning like a top

[Matman1110]

I found my ice blue zebra cichlid with its tail stuck in the side of the filter where it vaccums water in. I turned off the filter immediatley and the cichlid was released. Immediatley after that he started swimming very awkwardly, as if he had just had 18 shots of tequila. He was spinning/looping/twisting/flipping around way out of control. After about 2 minutes of that he was at the bottom of the tank with his head on the surface and his tail up and he was spinning like a top. At this point i removed him to a separate bucket and now he is lifeless on the bottom, not moving at all.

I already know he is going to die but i had some questions.

1) what was he suffering from?
2) is it contagious/should i be worried about my other fish?
3) could all my decorations/filter have been infected?

I plan on moving the fish i have in this tank plus some of the rocks and filter to my main tank. That is why i am asking this. Should i be worried and what should i do?

Thanks in advance