I wish I'm good at this, this is a very rewarding task. 3 BTC is a huge money for now.
Good luck to whoever can recover this and to you OP, you might be holding more money on that wallet.
If you are done with your useless post then let me be real to op. Hi you will not get your money from this wallet. Either because you are lying and you are the thief in the first place. Sorry if that offends you. Or simply because brute forcing the password of a btc core wallet has never been successful and would take hundreds of years ( at the least ) for a decently strong password.
Hard to ignore this, so who do you side with in this situation
I could do a walkthrough of btcrecover as I have done something similar before, in spite it been for the
bitsend project.
If OP is comfortable with this I can start but will require an escrow be setup and funds will be released after completion.