If you had to enter a password to use your wallet it must have been encrypted.

There is software available that cracks password protected multibit .wallet files. If you already have the password it should quickly recover your keys. However I have no experience of using it, and if your .wallet file is corrupted that software probably can't recover any private keys from it.

This guy developed it.

https://bitcointalk.org/index.php?action=profile;u=1171

These are the download and installation instructions.

https://github.com/gurnec/btcrecover/blob/master/docs/INSTALL.md

This is a quick start guide.

https://github.com/gurnec/btcrecover/blob/master/TUTORIAL.md#btcrecover-tutorial

My Bitcoin address is in my profile