What is your definition of psychology ?

I've been looking everywhere online for advice, and everyone I talk to says I should go to some sort of psychotherapy. I don't know about it, though.. I finally had the courage to tell my sister what's been going on - I've been hallucinating, I can't sleep too well (3 hours a night is my current average), I get very nauseated whenever I eat so I've lost a significant amount of weight. There's headaches, dizziness, fear (of nothing, really), anxiety, trembling, it's hard to breathe sometimes, too. I had a panic attack about two weeks ago, it lasted for maybe fifteen minutes. My dad says he used to have panic attacks, and I read somewhere that it's more likely for me if it runs in the family. I can't stand being alone because these hallucinations get worse when I am. I'm also being cold(-hearted) lately towards my mom and sister. I feel very anxious -at night especially- and self harm calms me down. I started scratching my wrists and digging my nails into them. I don't want to do this, but it's become very addicting and even soothing. My sister wants me to see a psychiatrist, and put me on anti- depressants. What should I do about this? Please help.

this is going to be my first post, i'm not really sure where to start this post so i'm going to jump right in, i have a been wondering lately whether i may suffer from borderline personality disorder, i have had this feeling for a long time that i am not quite right, i have this emptiness inside me, it feels like i am a camera stuck on live feed but no ones watching, i often feel like this regardless of whether i am content or unhappy.

onto how i feel, sometimes i lie awake at night reliving the past day, i feel ups, downs, and sometimes a cold icy rage. i have little control over my thoughts and feelings at these times, or anytime really. i can maintain at times, but only for seconds before i'm lost again. during the day when faced with interactions with people at work etc. i wear a mask that's all smile and charm, at times it feels more real than others. when like this i have little room for empathy or genuine care and affection, because one chink in my armour it could all come crumbling down. regardless of this, time, tiredness, stress and everyday interactions slowly erode it away. the harder i try to keep it on the worse the emotional comedown is. at home i can hide away in a book or hobby, at work i will feel like a zombie, just going through the motions, lost.

i have always known that i have a very adaptable personality, it became more clear with a friend recently pointed out to me, that i completely change, interaction to interaction, almost instantly, depending who is around, effectively becoming a different person. i think i choose the path of least resistance, the easiest and the safest. at times it feels like i am just mirror, lost in someone elses reflection. my lack of self has made me easy to be manipulated and used for the benefit of others at times sadly.

the people i allow myself to care about seem to effect me the most, i don't wear a mask with them, even if i wanted to i can't , this can result in myself becoming this mirror colored thing, for the most part i don't mind because we are happy, and i am more comfortable asserting myself, or the self i want to be,

i think this has been a pretty long post, i will leave it here. if there are any questions i will be happy to answer them. thankyou

Hi guys ,
This is pretty awkward to me talking about anything related to therapy to anyone. I've been seeing my therapist for a month now , we had 4 sessions and 3 walks so far. What i wanna talk about is how i can open up to him and not feel so stiff around him and end up regretting not saying all i want or any of it at all. He says we have a good relationship but it’s different for me. I feel really disconnected. I have so much to tell him but it always ends with me not saying what i REALLY wanna say , especially when we have a walk. There’s that thing i do when i feel "bad" , i pretend that i'm telling him what i'm feeling so i calm down. Maybe it’s the reason i have nothing left to say ?
The reason i'm trying to find a way to be more open is that i feel forced by myself. I’m regretting everytime i see him and end up not saying what i feel at all , and i don’t wanna drop therapy. I really really need it. I had a really unpleasant event by the time of our 3rd session and it made me realize how lucky i am to have a therapist at all. I wanna start fresh and on good terms with him. I wanna trust him enough to be comfortable around him to make our process better and not feel pushed. And he’s just a nice person idk what’s wrong with me
I want to want to get better and not feel so forced by myself.

Obviously I'm going to know the answer, it's just I want to hear another persons opinion.
I'm a 16 year old girl and I like fantasizing about things, sometimes it's actually meaningful and sweet, then sometimes it's just dirty sex with this guy I have been dreaming about lately.
I dunno what drives me, but it turns me on so much to be "dominant" over the person, not like "chains and whips" (No, not at ALL) but in a way that the other person can't say "no" to?
Who knows, I'm pretty sure I'm a pervert but I don't really know why or how I became one.
(^-^)