'Flutter/Flutter.h' file not found iOS XCode but it worked before

I tried every possible solution presented on the internet regarding this issue. The weird thing is that running the app worked yesterday and it successfully ran on my phone and I was able to Archive it so I can publish it. But when I checked today to take mockup screenshots, the build gives the Flutter.h not found error.

I tried

1. pod deintegrate, pod install, pod update, etc

2. Removing cache

3. Moving project files to another project

4. Removing podfile

5. flutter clean, pub get, upgrade, doctor, etc

6. Removing Flutter.podspec

The only solution I have yet to try is updating XCode and this is because I don't have enough storage for some reason (I have 40GB and update is 12GB)

The full error:

Lexical or Preprocessor issue

    Flutter/Flutter.h file not found

        In file included from Users/name/Developer/projectName/ios/Runner/GeneratedPluginRegistrant.m:7: