Rather than defining all of your functions in a single .psm1 PowerShell script module file, you might want to break apart your function into individual files. You can then dot-source these files from your script module file, which in essence, treats them as if they were part of the .psm1 file itself.
Consider this module directory structure:
\MyCoolModule \Functions Function1.ps1 Function2.ps1 Function3.ps1 MyCoolModule.psd1 MyCoolModule.psm1 Inside your MyCoolModule.psm1 file, you could insert the following code:
Get-ChildItem -Path $PSScriptRoot\Functions | ForEach-Object -Process { . $PSItem.FullName } This would dot-source the individual function files into the .psm1 module file.