You don't provide enough information about your situation, but, yes, you can sue. You'll probably have to go to small claims court because it doesn't sound as though a personal injury attorney will take your case because there are going to be serious issues with your credibility.
I'd be curious to know exactly how your stories didn't match. Did you provide a written statement. I'm assuming the version you gave to the police and/or your written statement differed significantly from what you testified to in court. (And, any personal injury attorney would have given you the thumbs up to testify in court. If, by claiming your lawyer's office gave you "bad advice," you mean it was bad advice to said it was fine to testify, you are mistaken. If you didn't pursue criminal charges this would make your civil case more difficult to win but a conviction of the defendant would make your civil case a slam dunk. Plus, that the DA "asked" you to go to court was a courtesy as the DA could have issued a subpoena and you would have been required to show up.)
Again, if I was considering representing you I would want the original police report containing your declaration and the trial transcript of your testimony to find out exactly how your story changed. If there is a valid reason/explanation for the different stories, perhaps your credibility could be rehabilitated but if the stories are SO different it would be unlikely a judge or jury would believe you.
If you don't give her the phone she will INSIST you do, and by you not doing so tells her EVERYTHING she needs to know anyway!!!
Just bite the bullet, give her the phone and prey she doesnt see whatever it is you are hiding and remember to DELETE everything next time - never take risks when you are upto no good!!!
However, if it were me, then I would promise not to go down your phone, but I sill would!!!
Your gonna be mince meat, Slip and fall................more like CRASH AND BURN!!!