Now That I Live Alone With My Mom, She Takes Her Stress Out On Me!!!!!!!1?

So, my older brother and sister went to College, and i'm 17, a junior, and am an A, AP student. I often feel like when she is stressed she likes to blame me for things going on in her life. I do what i can to help her, i believe i really do! but she gets angry and says things like "You Never do anything for me, i always have to do things myself, you always think about yourself" and when she says this, she is talking about me cleaning the house for her, which i do every once in a while, not all the time, but to say i "never do anything for her" is a definite stretch. She also goes into "Its always "mom will do it" or "it's mom's job"" but, she doesn't do any more for me than any other mom does, in fact, i like to think i'm quite self reliant. And she always makes a huge deal about whenever i do something wrong, or mess up just once! when i forget something, or if something short notice some up, she claims that i should have done something about it much earlier, and she has a point lots of times, but whenever i try to explain why something happened, or if i even question it, she comes back with "why can't i ever say anything to you without you making up excuses", and i see them as a reason why i made that mistake, which i believe is an appropriate response when she is tearing me down. And if i question her argument like "name just one time when i did that" and she can't come up with one time, she says "I don't know, i guess i'm always wrong then", and then she starts to cry. she claims i always get defensive and that she come back with "might as well never say anything to you because it makes you upset and defensive" and i do get defensive, largely because the way she points out and makes a big deal out of every mistake, feels like an attack against how hard i work, or against me.but that fails to be the part of her that annoys me the most, she expects me to do (or not do) things that she doesn't do (or does do) herself! an example of this would be her need to compare me to herself when she was my age, because she took care of her other siblings (she was oldest) yet whenever i compare her, or even myself to ANYTHING whether it is good or bad, she says that i should never "compare yourself to others". and it makes me want to say something, but usually i try to remain in a completely calm voice, and not say anything about it, even when she is yelling in my ear. another example would be something that happened just a few days ago. I needed to wake up at 5:15 in the morning, for a trip to Charleston (SC), so i set my alarm, and she is usually my back up, so i told her, "if i'm not awake at 5:25, wake me up please." and she ends up waking me up at 7:10, 20 minutes before the bus to Charleston, because she forgot, and She got mad at me because i didn't plan better and, and all of these other reasons why it is my fault, and i end up taking every little bit of fault, with the whole "you are right, you are right, you are right etc....", (I end up making it barely in time, even though my school is 25 min away). then i return, and that very next morning, I had to wake up for a 5k at 6:00 in the morning, and she had to go to work at 6:30, and she said that she would wake me up if my alarm fails again, and she also said that she would have to be up all night doing work. so, i wake up when my alarm tells me to, around 4:15 ish, and i assume she is working, so i get all ready, and i look in her room, and she is asleep, so i wake her up, and she preceeds to tell me she didn't awaken from her alarm, and she starts yelling at me because i didn't wake her up before i got ready, and instead, woke her up when it was time to leave the house, and keeps telling me how it was completely my fault, and i take every bit of it, even though in my head, i keep yelling to myself "THIS IS THE EXACT SAME THING YOU DID TO ME YESTERDAY, YET THEY ARE BOTH MY FAULT?!?!?!?!?!?" it makes me want to explode, but i know if i even try to defend myself, she starts telling me how i always feel the need to protect myself, or how she feels that I make her always seem wrong, and how she feels she cannot say anything to me without me getting defensive, and she cries she she does this so its hard to argue back. She does these things when she is stressed, which is a lot of the time. (even though when i bring it up, she claims she never does things like this). Another aspect of her is the fact that i cannot blame her for anything without her responding "why do you always look for everything I do wrong??". And (at least it seems to me) I never blame her for ANYTHING (out loud)! and when i do she responds with this. she is really a good mom, and she works hard, and she isn't like this all the time, but when she is, i want to explode, and i feel i can't bring it