Name mix up at the CRs

I have a weird problem. My parents decided to name my self and my sister with "Rhyming" names. The problem is my sister is a dead beat. She doesn't pay her bills, she has had 2 bankruptcies so far, and she is about to file for a 3rd one. She's 31 years old.
Because her name is Terry, and my name is Kerry, I find her collections on my CR all the time. I pulled a credit report in June and I was ok. Well, yesterday one of my credit card companies let me know they were dropping me as a customer. When I asked why they said because my credit score has dropped significantly.
I pulled my equifax and they have my sister's name Terry as one of my aliases but only my social security number. And my credit score plumeted 110 points. I also have collection accounts on there that I know are hers. I will send them a DV letter adding that I am not Terry, nor have I never been.
I have a note on each of my CRs saying that Terry is not me, but my sister, I renew it every 3 years. I learned that one after her 2nd bankruptcy showed up on my CR.
I called Equifax and they said I needed to send a copy of my Social Security card as well as my drivers license to prove it's me. I was planning on including a letter with the documentation. Any idea of what I should say? I'm just so frustrated that I spend all this time cleaning up her messes. Is there anyway to prevent this from happening again?
Thank you!

Unfortunately, this is a common problem. You need to send proof that you are NOT your sister (the ss card and your driver's license should do) and the incorrect items will be removed. It sounds to me like you taken many steps to try to prevent this from happening already. Is it possible your sister is using your name purposely?

and because of that going on, I'd would be placing some type of statement on your CR to ask for multiple ID's to prove who you are....make it harder for her to just get your credit....my guess is shes using your SSN....which stinks....hopefully, she doesnt have anything criminal outstanding on her as well...cause you'll get popped for that and it's a mess getting it fixed at the courthouse and in jail....

She isn't. She's irresponsible, but she won't steal like that. What seems to happen is she doesn't pay her bills, then the CA's start looking for names, and because she use to live at home with our parents and so did I, they find the common address and end up assigning it to me as well. It's very annoying.

What a bummer. I think you're on the right track, having a statement on your credit report that explains the situation. Of course, CAs aren't likely to pay attention to it. Good luck to you!