SQLite isn't really designed to handle concurrency. If you're dead-set on accessing an SQLite database from multiple processes, then you're going to need to write the code to detect and handle errors of this type for yourself.

The saner approach would be to switch to a database engine which is designed to handle concurrency, such as PostgreSQL, MySQL, etc. It would be much easier, plus it would provide a solution which is vastly more robust than any kind of homebrew concurrency handling is likely to be.