I feel really bad about it. I want the domain but the price I bid at auction is so high I can't go through with it.
The important point I see is that YOU bid. I agree with what others have stated: "you should pay" - "man up" - "reputation on the line" etc, however the root issue I see is:
Why bid a price you are not happy paying?
This is potentially: Unprofessional, silly, stupid, reckless, careless, unethical, not giving a turd for other people who now have to relist and who will possibly miss out on all the previous bids as people knew what it was bid up to and so don't bother this time.
In fact, ironically you stated your worries of "other bids could be shill" when yours turned out to be a fake bid. So what if none of the other bids were shill?
You then were the only one with a fake bid.
Honestly, we all make mistakes, but logging in to a website with username and password, finding a domain name, clicking "bid", typing a value into a form box, and clicking "enter" is not a mistake!
I haven't disliked your post as you already have plenty of those, and (weirdly, I think) also because you owned up. I'm not saying owning up makes it ok whatsoever, not even a little bit, but it's interesting you come forward publicly with something you must have known you'd be chastised for on a pure domaining forum.
For that reason, I have to throw psychology 101 at you and claim you know you did wrong and feel bad and wanted a bit of online kicking.
Seriously, don't bid on a price you don't want to pay.