Container data problem

Sorry, I opened another question.
The last question is about dfx deploy.

This is to ask about my production data in the container. Since I realized dfinity, I have been amazed. I think this is the real blockchain project. This is what I want.
I quickly deployed some projects using official documents, and some projects were used in external production before.
It has been healthy to use before.
Since a few days ago, dfx deploy has been unable to deploy. I found that the data in my container is no longer available. These data are the data filled in by the user. As a production project, these data are very important and very important. If lost, it will become a major production problem.

When I tried to read the data using the method I wrote, the front end reported an error:

actor.js:122 Uncaught (in promise) Error: Query failed:
  Status: rejected
  Message: IC0504: Canister vepay-hiaaa-aaaaa-qbdnq-cai violated contract: ic0.msg_reply_data_append: application payload size (2786666) cannot be larger than 2097152

I know that this prompt means that the read data (2786666) is very large, but when I write a method to obtain a certain part of the data, my code can no longer be deployed, and the deployment prompt keeps saying that the subnet memory is insufficient, until I ask a question It’s been several days now.

Where can I get the container data I want?