I'm sorry but reading the total amount of coins lost especially 350+ btc made me skeptical.
With such amount of holdings, you should know already that you should be keeping them in much more secure type of wallet. With such amount, it also give us an impression that you have had a lot of experience in the crypto world that should tell you that recovering it is no longer possible.
But with all these thoughts, I'd still incline to trust your words that you lost such amount because regardless of how much you actually lost, it doesnt change the fact that it cant be recovered; so im sorry for your lost.