WOOHOO I got mine to work again!
It is almost 5 am and I have been messing with this for a while, so I will try to explain everything I did, hopefully in the right order.
What I did was to plug in the SD card that I used to put OSX on the computer in the first place, when the Dell splash screen is up press F12 for Boot Options, then I chose USB Storage. A grey screen with Mac 10v (my HDD) and Mac OSX Install DVD (my SD card) came up and I chose the install DVD, then the grey screen with the Apple on it came up, I crossed my fingers, and the loading pinwheel thing showed up after a while. Then a white box asking me if I want to install OSX came up, but I chose to go to Utilities across the top, open up Disk Utility and tried to repair the HD and repair the permissions, upon restart things were still in an infinite startup loop, so I went back to the install screen and said eff it and re-installed OSX, it took probably 45 minutes, BUT the best part is once it was done the computer restarted normally, and everything was just as it had been before the computer got jacked up...oh and iTunes was updated. haha
Sorry for not being more technical about my little how to, but I'm not as computer savvy as I wish I were, and my geeky husband has been asleep for hours now, and I really wanted my laptop to work again. So, hopefully this works for you and anyone else that has this problem. I'm going to bed feeling smug and pleased with myself.