What is your definition of psychology ?

Okay, I've been searching for help. I have a problem. Let me start from the beginning.
My eldest brother suffers from cerebral palsy, and my entire childhood- my mom did not stay with me (parents are not separated) and my dad isn't exactly the loving type.
I have been a liar (without meaning to) from my childhood, and I have been sexually abused when I was a child (it didn't feel like an abuse, though)
Growing up, my elder brother (another one) kept dominating me or comparing me with my cousin brother who stayed with us. My brother would even force me to do things I didn't want to. He literally used to twist my arms.
Slowly, I feigned love for him. It happened on it's own. I actually believed myself. I knew I found him irritating and unwanted but still I respected him.
The somewhere around highschool, I got into a relationship and got cheated on. Yes, it was my first love.
It hurt. I was in a boarding school, I felt alone but never cried. I tried to take my life for reasons I can't remember. That phase of my life is a blur.
I thought everything would be okay.
It didn't.
My dad took me to a therapist, but my mom felt I was possessed by a spirit.
I'm 16 now, but I still haven't rebelled or gone against my parents.
Anyway, I never met the therapist again but I had to take part in rituals and what not.
Back to my brother, he manipulated me and made me look bad in front of my parents.
Being the weak, submissive sister I was, my parents never thought it was my fault.
Moving forward, he even made me lift up my shirt because he wanted to see my body type. I was obsessed with losing weight, I was dumb, I did it.
Now he would hug me weirdly and said I never hugged him properly. It sounds funny but he said my butt was too outwards, it should be inwards towards the person I was hugging.
Now, back to my elder brother, I know that he is suffering. But he does so many things to get attention. Shouts, screams, cries all day long. I'm suspecting that he even feigns illness. It isn't that we don't love him, we do. We do everything he asks, but still...
My father has never been affectionate. But he has always been there for me. We're good friends.
My mom, I don't know. She always makes me feel that marrying dad was a mistake. We're good friends, but... I feel trapped. Everything I do has to be under her.
I can't do anything on my own.
I feel suffocated.
So, around five months ago, my elder brother died. He was an alcoholic. He hit me, we fought. I never spoke to him again. I guess, I never will. I hadn't seen his face for a week or so, and when I did... I knew it was lifeless but it didn't look that way. I can't accept what happened. I'm angry that I couldn't be angry at him anymore. I don't know.
Now, I'm rude to people. My teachers say that I have lost that shine. My writing suddenly improved. I can laugh but still I feel different. None of my friends talk to me. I only have online friends.
I feel so alone.
Sadly, I think I like it that way.

Ok, so I'm pretty sure there is something wrong with me. I have had this feeling toward my stepmother since I could remember. Like a desire. I know it's wrong, it's not right because she is married to my father and she is my stepmother. My father cheated on her and I just wanted to tell her so bad how I felt about her, and how much she deserved better but they got back together. My father married her without telling her he had a vasectomy. And all these years later she really wants a kid, I wish I could help her have a kid...
I am 21 years old, and I moved back into their house about a year ago because my roommate moved out of state and left the bills all on me. I go into their room sometimes when they go to work and I smell her freshly worn panties, and masturbate to them. I found a box of her toys(dildos) and I masturbated to them and licked them. I also found their sex tape and watched it so I could see what she looks like naked. Sometimes when my dad leaves to go to work, I hear her getting into the shower and I fantasize going in there and joining her, or going into the room and waiting on her to get out.
I have control enough to never do anything to crazy, but what should I do? Should I just get help, or tell her what I have done/ how I feel, or nothing? Please don't comment how sick I am, and how I need to find god.. I know I am sick, I just can't control myself sometimes.

so i have d.i.d. (dissociative identity disorder) and one of my alters is named benji. benji is an 8 year old boy in the body of a 18 year old biologically female. i have no issues regarding my gender or sex and feel i was born in the right body. benji has such bad dysphoria that he hates coming out, refuses to look at himself in the mirror, refuses to take pictures, and everyone can feel how much sad it makes him. last night was the final straw though when my mom wanted to take pictures and he was co-fronting with me he started to cry because he asked her why she needed to take them. my mom dismissed his feelings and i just want to help him. anyone have something similar to this or have any ideas on how to help? i am so lost right now...

Okay so I caught my fiance using my email to find girls on Craigslist o guess to have sex with. I was just going through my email and happen to see it i know it wasnt me because that was the night he was using my phone while i stayed at my mom's house amd some of the things he was messaging to these girls was really upsetting I confronted him about it at first he insisted he didnt remember ever doing it Then he said he might have had a moment of weakness. Then he kept insisting on how We changed in a good way because while he did that he said he realized he loves me amd I'm the only girl in his life and that he only wants me. And. What really bother me is that this happened not even a week after he proposed and altogether We been together almost three years and We have a baby on the way in less than two months. Before all this I would find porn on his phone Where he would watch it or download videos or pictures and it really makes me feel like crap. I mean I know I'm nothing really to look at I put on thirty pounds while being pregnant and sometimes it's like he don't want to touch me like he is completely discusted by me and it's always like he wants some super skinny girl that he can wrap his arMs around and have sex with all night I mean We don't even have sex like We used to it seems like he is watching the TVs more than he is even looking at me I can't really lose weight right now being pregnant and all. I don't have the pretty face or the perky boobs that he wants I just wish I could magically change how I look completely. I Love him so much I would spend all the money in the world to be the completely sexy girl he wants. D':