I wanted to say something encouraging but this actually sounds like the end of your motor.
It's possible that you could free an outboard that seized during storage but I think you're talking about one that seized while it was running. That is very different.
With the description that you give of running it out of oil, I can't see how anything less than replacing the power head with a rebuild or another power head will help you.
Even if you get it going the way that it is, you'll still have big problems.