Do what the handbook says: Leave a friendly and welcoming comment and a Closevote.
Recently I interacted with a similar question (1) and did what the handbook said.
The user reacted in one of the more positive ways: He posted a thankful comment that someone explained him the problems in his question and deleted it with the prospect of asking better scoped questions on another day.
Sure that won't happen every time, but every time that happens we may have gained another valuable member of the community who will bear his load of the queues as soon as he has rep enough.
This was the very first time that someone explicitly thanked me for being friendly here on SE, but the point is that with patience and persistence we can build a community where there are many shoulders that bear the load. I think we are on a good way there.
If you are emotionally at the point where you can't stand the crap anymore, take your time off, come back and work the queues when you are ready again. I'll do the same on SO. When I have the time I work the close-queue there, but after a day or two I don't want to see the crap anymore so I stop it and some weeks later I start again.
1 This one for people who can see deleted questions.