This sounds like an ideal case for accepting your own answer. Go ahead.
To answer your questions:
Is there a way to pass the right to accept answers to another user or a group of users?
There is not. You retain sole agency over the accepted answer. Not even diamond moderators can change or set an accepted answer on your behalf.
Generally speaking, is it considered bad etiquette to accept your self-answer?
It is not. Doing so is totally OK.
FYI: When a querent accepts an answer they wrote themselves, the answer isn't pinned to the top like usual. Instead it's just sorted in regular vote order. This means your self-accepted answer wouldn't appear on top anyway unless the community thought it was good.
Is there a way to handle this delicately (beyond leaving the question with no accepted answer)?
It doesn't need delicate handling; it's fine. It's not a delicate thing. You did well, and past-you would have accepted that answer. You can accept it now. The only kind of handling it really needs is to act in good faith about it, which you're doing.
I'm concerned you'd be worried where you sit regarding good faith or bad faith usage of the checkmark, so let me illustrate what bad faith means here with a specific behaviour pattern we see from time to time: bad-faith visitors sometimes come by to ask questions fishing for a very specific (but wrong) answer: they want to win an argument or have their way in a game or something like that, and they want us to back up their side, but that's not our business. Our business is correct/good answers and they get upset at us when we provide those and they're not the stance they want to hear. They'll argue with anyone and everyone for days about it, insisting every answer is wrong and should be “fixed” to represent the querent's desired stance. Sometimes, after days of arguing with us inevitably fails, they'll leave their own answer with the stance they wanted and accept it, and because it's wrong and they're being a jerk they'll subsequently get downvoted to oblivion.
If that's a yardstick for bad-faith behaviour with using the self-accept button, you're nowhere near it. You just have a good answer, you've neutrally assessed it's pretty good, and you've done legwork to get it into that shape. Feel free to accept it.