Oh hey UltraRPM. Well, yeah, that email has probably lowered your chances significantly. Your options are quite limited at this stage.
1) Buy your domain name with an alternate TLD (ie: .net). I recommend
DomainMaze (a reseller of Enom that is run by an associate of ours) - it'll be fairly cheap. Don't go looking for an alternate TLD, planning to buy it later. Make sure that when you go searching for the domain that you are ready to buy it there and then. Owning the alternate TLD will mean that if you cannot get the .com TLD for your domain name, you will at least still have something to go on.
2) Beyond the above, try and ignore this for the next 5 days. Don't go doing any further searches for the domain or your own name on Google. Once the 5 days is up, try and register the .com domain straight away - the same goes for timing here as in tip #1. If that fails, try the deleted domains registry on whois.net (or google for an alternative to whois.net). If this fails, you will have to fall back entirely on #1. You could try submitting a complaint to ICANN, but you'd be as well submitting a formal complaint to Sudan about Darfur.
Unfortunately, they now know that you are interested in the domain and a Google search will prove that there's some traffic to be had from it.
ICANN's 5-day taster registration is the dumbest fucking idea ever. It wouldn't surprise me if they were getting kickbacks for this.