Would you be mad about this?

Today, my mom told me that she read my phone. She had no provocation to read my phone. I don't do drugs, have no "shady" friends, haven't changed my behavior (aside from the usual teenage girl mood swings, but I can't help those), had amazing grades in school, am a good citizen, healthy and active. I happened to leave my phone lying on the couch, and I fell asleep in my room (I had a nasty case of the flu :/) She told me today that yesterday, while I was taking my nap, she decided to "play" with my phone. My dad has the exact same phone as me. He was awake and home and not using his phone at the time. (I know this because he was working in his workshop all day and ignores his phone when he's in his "Zone"). My mother then preceded to read all my text messages. I happened to have some very old ones saved, from a few months ago. I had forgotten that they were saved in my inbox still. My mother says she was just playing, and "happened to somehow end up in [my] inbox." These messages were at the very bottom of my inbox and obviously weren't easy to find, considering I, the user (owner?) of the phone, had forgotten about them. The messages had no name on them, just a number. This is because I had deleted the contact from my phone. It was the number of my former best guy friend/on-off-on-off crush, whom I'll call "Kevin." They were of him begging, pleading, bargaining, threatening, cajoling, and eventually receiving, a topless picture of myself. I regret it immensely, and it has taken me a lot to get past my guilt and what I did, not to mention several weeks tips in expensive chocolate-therapy, chick-flicks, and sleepovers with my besties. I learned my lesson, and will never do it again. I know for a fact the pictures are no longer on "Kevin's" phone, and were not sent to anyone or stored anywhere by him. I had a fairly close relationship with my mom, but I had not told her about my picture fiasco. She figured out what happened by the saved and forgotten messages. She then confronted me. I told her the truth, and that I had learned my lesson, and will never do it again. But, she kept trying to pursue an issue that I have worked hard to bury from my mind. I didn't want to talk about it. I know why I did it, and so does God, and thats fine with me. I didn't want to dredge up all the regrets and memories that came with the long talk she was hoping for. She decided it would then be a good idea to remind me of it all day, after I made it clear I didn't want to be reminded of it, and then make "jokes" about me and my body that were hurtful. I am very angry that she looked through my phone, then wouldn't let an issue die that should be long dead and buried. Would you be mad? I'm livid. She does pay for my phone, even though I've offered many times to pay for it, so I know she technically has the right to look through it. But she should've asked me, not snooped while I was sick and asleep, and then lied about her intents. I would've taught her about my phone if she honestly want to learn about it. Why couldn't she leave alone the picture thing, even after I made it clear I didn't want to be reminded of that, and that I had delt with it? Can I ever trust her again? Because I have no trust in her right now. I feel very violated. She said she want us to have "an open, honest, close, sharing, trusting relationship." But that should mean she doesn't read through my phone while I'm gone and respects my feelings, right? Thanks for your opinions. I kind of just needed to vent a bit, but I want to hear what you have to say. Sorry it's so long, but I wanted you to understand the story.