I've had a similar reaction recently. I haven't hit THE number (not even sure what it is), but I hit a significant number and found myself subsequently reluctant to check my balances. I just don't want to see it go below that number, even though I know it will and I know it's normal and I know it'll come back up (and go back down). I think I'll be a mess when I get closer to retirement, and am not sure how I'll handle it. Perhaps I'll aim for a 3% withdrawal to feel "safe?" When you don't have a lot of fat in your budget, it's harder to flex your spending from year to year. And though, in theory, going back to work is always an option, I worry about not being able to find a job after having been out of the market for a long period of time.
So, yeah, I think I will be vulnerable to OMY syndrome. I suffered from TMY syndrome in my corporate job--thought I'd work there 2-3 years when I took the job, and said countless times over the years, "I just need two more bonuses." Finally, after 12 years I got the courage to leave and move to the non-profit world.