What did I do wrong?

        My kids...today...they bug me. I ask my little one to get her backpack so I can review her papers and sign her log, she wanders off and about two minutes later is still walking in little circles saying, "I don't see my backpack." It's RIGHT THERE!!!!!!!! two feet to the left of you, on the foot stool! "oh, mommy, why didn't you just get it if you knew where it was?" ...blink, blink
         I make my coffee and my youngest teen says to me, "Can I have some of your coffee, but iced?" me, "uh, no." "But WHHHHYYYY?" "because you don't even eat breakfast, because you're thirteen, because it's mine and I don't want to share just this one thing, you use my make up, you wear my clothes, you smell like my lotion, I have to yell from the shower to get you to return  my conditioner, LEAVE my COFFEE ...alone." her, "ugh, fine" blink....

My oldest teen, her room, food sort of ..everywhere. I go in to say good morning, but realize that I asked her to get the food out of her room DAYS ago, and yet, there it is. I can sense cockroaches converging on our house just looking at that food on her dresser. Let's walk through that lovely conversation shall we?
"Baby, could you PLEASE get the food out of your room like I asked?"
Her, "Ugh, did you just come in here to nag me?"
"No, I came to say good morning to you and your pet roaches, and I'm not 'nagging' I am politely asking for the umpteenth time before I lose my patience and start yelling:"
Her, "I picked up the food! It's over there in a bag! SEE!"
Me, blink, blink, blink..."I asked you to get the food OUT OF your room, not make a doggie bag for the bugs and rodents. To have  complied with what was asked that bag would need at the very least to be in the hallway."
Her, "I have to go, I'm going to be late for school because you're nagging me"
Me...blink, blink..blink....

I'm a good mom, hubby is a good dad, we work hard to be fair, balanced, involved, caring, intelligent parents. We've tried hard to instill work ethic, respect for oneself and others, compassion, intelligence, common sense in our children. On days like this, I suspect, we've missed something, lol. I'm angry with the kids and more importantly angry with myself because I don't think I handled these scenarios properly, but to be honest, I have no clue how I could have approached them differently. In general terms I have wonderful children, it is only their father and I they feel the need to drive very fast and very far down a very short pier...they argue with almost EVERYTHING we say. I want to strangle them sometimes. They even know the cues that they are pushing me too far, my middle daughter informed me that the more agitated I become, the more slowly I blink, lol....she KNOWS this and yet still pushes me beyond "blink capacity" into YELLING territory! Yep, it's Thursday and today, I'm NOT feeling like the most successful wonderful mother in the world. Maybe tomorrow.
*I finished writing this, got up to refill my coffee and felt a cold breeze blowing through the house...they left the back door standing WIDE open...I asked them to let the dog out, which amazingly they did, but apparently closing the door was just a tiny leap too much, lol...help me...