But hey! Life goes on! Let's look on the bright side:
-Your mom is still alive (as are all the people you care about)
-You're still in London, still having fun
-Your sister and good friend are still coming up to visit you next week
-A nice boy walked you to the US Embassy this morning, perhaps out of obligation and a reluctant sense of chivalry, but nevertheless, he walked you.
-You made an appointment with said Embassy, and they said that you'd have an emergency passport in time for spring break.
-You have two lovely roommates who were very concerned about your well-being/whereabouts last night/this morning.
They say that bad decisions make good stories. It might take a few weeks for the rawness of this particular flub to fade out to good story material, but everything will work itself out.
Life goes on!