What is your definition of psychology ?

I am a sixteen year old female who is sexually attracted to her own mother. I'm incredibly ashamed of it and I have no idea why I feel this way. I don't find her attractive. And I've actually had an absolutely horrible relationship with her ever since i was 13 and I cannot stand the woman.
Honestly, the relationship is so horrible. I have trouble hearing her voice without getting incredibly pissed off. But recently I've been getting so angry, that I actually become turned on. Now, the littlest things she does that used to make me so angry, now turn me on. For example, the way she handles everything so delicately, how soft her voice is...ect. ect.

I've been feeling this way for about 6 months and its been progressively getting worse. Now I find it invading my thoughts, and being on my mind frequently.
I have struggled with OCD in the past... Obsessive thoughts about things such as incest and bestiality .. but I've never had problems with obsessive thinking AND erotic feelings.

Please. help. I've attempted suicide because of this, and I haven't been able to bring myself to tell my therapist or psychiatrist.
I have looked on some forums saying that feeling sexually attracted to a family member is more common than people realize... which makes me feel a little bit better.

But I would like to know why on earth do I feel this way? And how can I make it go away?

I have been wondering this for a while now. Ever since I was little, my Mom tried to fit in with her boy friend's life style. The guy could have been a raging alchoholic, who was a complete ass(most of them were) and she would stay with him, no matter what. Last year, I told my mom that my step brother had been sexually abusing me for a little over two years. When I told her, she at first seemed shocked and had called him in the room with my step dad. They kicked him out of the house for two days; during those two days, my mom didn't talk to me, yet alone speak to me. She began making me feel guilty for getting in trouble, and even tried bribing with my graduation dress for my 8th grade ceremony. I eventually gave in, and they moved him back in. I was forced to live with him for six months, until I ran away to my dad's house. The thing that I have had trouble coping with is how she could have just turned away from me. It hurts so much. I would have maybe understood if she was a dad, since they don't really go through the pregnancy and the pain mothers feel. I have just have had the hardest time grasping how my mom could have just left me like that. She told I could tell her anything. Why would she have done that? I'd like to assume she just has some mental illness that she had never told me about, but maybe she just didn't care what happened to me.

Thank you for your time
I am currently a male upperclassmen in high school. My grades are... For lack of a more accurate word bad, I have about a 2.0 cumulative. I used to want to be a 2d animator you know like cartoons. When I think about it that goal it is as far as can be from my reach. About a year and 4 months ago I saw this girl who is now the only thing I think about, I talk to her In very small conversations daily, she is the only reason I even want to go to school when I'm in class I zone out and just think about her I would do anything, everything, and more to make her smile. I go home from school too depressed that I'm not more to her than just someone to talk to for ten-twenty minutes and forget my homework and just think about her, cry for a few hours. Then my mother gets home and it's time for me to fake a smile and make sure she never worries about me. I usually talk to friends on skype which surprisingly takes my mind off of her a little bit, then nighttime comes and I'm back in bed crying,shaking, tired but too scared of how bad my depression may get if I don't keep working for her I've even caught myself whispering her name and talking about how much I love her when I'm in this state. So I'm trapped in this cycle, I ignore school and think of her then I remember she's the one and only thing I would ever work for and my grades just keep dropping. The one funny thing, nobody knows I have this problem, I seem so mentally stable, and I have plenty of friends, I'm only lonely because i avoid talking to people sometimes so I can just lay in bed and think about her. I had brought this problem to a different site and I was banned within a day (I must've swore or something) and I felt like nobody could help me, i have 3 ways I think of my life going, either I end up with this girl that I would be as loyal as a dog too, I somehow manage to pursue my dream of being an animator, or I don't end up with her and my depression takes over, and It scares me so much. Please just give me feedback, I need this help I feel empty.

I'm not sure what I should do, I had a dream and my therapist was in my dream, by the way the dream was NOT sexual. I am wondering if I should tell him about my dream or not????