Convert P2SH to P2PKH
Converting address formats is not feasible without knowing the public or private key(s) used to generate them.

Without reviewing the source code of btcrecover, I can't advise whether you should use it or not. But if you do trust it and decide to use it, consider first generating a new seed and address to immediately send your bitcoin to.

Consider any seed you may recover with btcrecover compromised and no longer secure.