Deleting alias (moving to trash) has ended in disaster!

Hi

I am very new mac as will probably become apparent. My problem is this; I have recently been taking a lot of photos on my phone and have been storing these images in Dropbox (my phones android, and so they don't get along) so I can instantly access them on my new mac mini (less than 3 months old). I decided i wanted to move the files from my reapidly filling dropbox to a more permanent setup. So i simply dragged and dropped the desired folder from Dropbox into finder but in my haste I dropped the folder into applications instead of pictures. This proved to be a fatal error.

Having realised this I tried to correct the mistake by reselecting the images/ video clips and dragging them over into pictures... Sorted. Apparently not. After some time of the little colourful wheel spinning. Nothing appeared to have happened, the files were still in applications in front of me. So I repeated the action, again the little wheel, again nothing moved. So I checked pictures. There were now 2 "copies" of all the files from applications. Job done I deleted the unwanted images from applications. Returning to pictures I realised that they were in fact not copies but instead "alias" something quite frankly I had never heard of. Disgruntled I realised I had deleted all of my actual pictures and replaced them instead with double the number of now apparently useless aliases ( I had of course in my wisdom cleared out the trash bin only moments before so the originals have gone). I must now admit that there was originally over 1000 images, which has now doubled to some 2000 aliases.

Being a novice I starting clicking the aliases to see if anything would happen, or more appropriately how to delete them. This resulted in that dialogue box I'm sure everybody knows about ( delete or fix) popping up after about 20 minutes of the colourful thing again. After various freezing, dialogue boxes and general delay I tried to shut down finder ( it was desperately trying to find loads of originals I knew it would never find and was getting in a tizzy) via activity monitor. This resulted in at first a denial ( a box telling me it was busy ) and then a virtual implosion as I rather stupidly tried to find the bit of activity monitor that would shut off the bloomin trying to find original thingy. With nothing but a blank screen in front of me I did the only i knew how. Turned it off and on again.

It seemed to work, the stupid things are still in pictures in finder but at least it booted up ok. This time I just tried highlighting a bunch of them and clicking go to trash. This took aaaaaggggggeeeessss. Eventually I got under 100 of them deleted. And then I gave up and went to bed. Today I have started to try again. Growing impatient of trying to delete them in tiny batches I hoped if I set them all to delete and leave it going eventually time heal the wound. Alas not to be. Highlighting them and right clicking to bring up the box that would allow me to say delete caused ( after 20 more minutes of whirly colourful thing) it to try to open the delete or fix dialogue box for every single one at once. With over 2000 dialogue boxes trying to open at once it took it nearly an hour to give up completely of what I can only assume was a mac mini version of a massive stroke.

The current situation is thus; me quietly trying to delete them one at a time but even this approach is taking nearly five minutes just for one to delete.

PLEASE HELP!!!

A) what have I done?

B) how do I fix it?

C) And how do I delete the bloomin things!!!

( pretty sure the operating system is completely up to date Mountain Lion if that at all helps)