I REALLY NEED HELP PLEASE AND THANK YOU?

[lowhook497]

So I used to be friends with a lot of people on twitter and I would give them my password and they would give me theirs so we all have eachother's accounts on our ipods/iphones. Now, I'm not friends with some of these people and I thought they would have the decency to stay off my account and revoke access or whatver, but sadly, I was mistaken. Just recently, someone got on my account and tweeted something and also dm'd a few people off my account, but it isn't someone I'm friends with so it is obviously someone that is mad at me etc. I know it was a dumb mistake in the first place, but is there any way I can figure out who it was? Can I track their general location because if I just knew a state I would know who it was. If anyone has any idea how to track info from a dm or a tweet, please let me know. There's no way I can figure it out and I'm sure it's someone on their iphone/ipod or whatever and just never logged out of my account and decided it would be funny to get on. I'm begging. Please help me, it would mean a lot to figure out who it is considering they decided to tweet mean things about me on my account.