The subtlety with the Ugh Field is that the flinch occurs before you start to consciously think about how to deal with the Unhappy Thing, meaning that you never deal with it, and you don't even have the option of dealing with it in the normal run of things. I find it frightening that my lizard brain could implicitly be making life decisions for me, without even asking my permission!

Relational frame theory is a theory of language cognition that attempts to explain this. The basic idea is that we form associations between thoughts, and when we think of an element in a relational network with another element that causes a painful emotional reaction (shaped as you describe), we have that flinch, even if the element we think we are reacting to is benign. And as you describe, this can lead to behavioral avoidance.

I'm currently in acceptance and commitment therapy which teaches you how to distance yourself from those thoughts and see them as language (and not the proverbial "tiger in the bush"). I'm not proselytizing (one of the more distasteful inclinations of a therapy patient), nor describing it in enough detail to be therapeutic, but I've found it much more helpful than straight cognitive or positive therapy.

After the top level post about it, I bought a bottle of Melatonin to try. I've been taking it for 3 weeks. Here are my results.

Background: Weekdays I typically sleep for ~6 hours, with two .5 hour naps in the middle of the day (once at lunch and once when I get home from work). Weekends I sleep till I feel like getting up, so I usually get around 10-11 hours.

I started with a 3mg pill, then switched to a ~1.5 mg pill (I cut them in half) after being extremely tired the next day. I take it about an hour before I go to sleep.

The first thing I noticed was that it makes falling asleep much easier. It's always been a struggle for me to fall asleep (usually I have to lay there for an hour or more), but now I'm almost always out cold within 20 minutes.

I've also noticed that I feel much less tired during the day, which was my impetus for trying it in the first place. However, I'm not sure how much of this is a result of needing less sleep, and how much is a result of me falling asleep faster and thus sleeping for longer. But it's definitely noticeable.

Getting up in the morning is not noticeably easier.

No evidence that it's habit forming. I'm currently not taking it on weekends (I found myself needing a nap even after getting 10-11 hours of sleep), and I don't notice any additional difficulty going to bed beyond what I would normally have.

I seemed to have more intense dreams the first several days taking it, but they seem to have gone back to normal (or I've gotten used to them/don't remember them).

Overall it seems to work (for me at least) exactly as gwern described, and I'd happily recommend it to anyone else who has difficulty sleeping.