20 characters long? Best way to hack is to ask FBI and NSA politely to give you all their ressources. I'm afraid you lost your coins. ALWAYS write the password on a paper, on a tatoo, on your ass, on your toilet paper, in your car, in the shower, everywhere if you plan to have a lot of money under a passworded wallet.
Nothing worse than loosing your money because you forgot your password.
Sometimes it's more risky to activate security than to take the risk being robbed lol. so be very cautious with crypto and password encrypted wallet : write it down, always.
and make copy of the wallet.dat in 5 usb stick, all your computers, and in all avaible external drives you might have.
Repeat every month.
yeah i know i'm paranoid
