I Can't Tell If I'm Psychic Or Just Imagining Things

I don't remember my childhood, or if I saw people, or anything. But I do know that in the past 3 years or so (I'm 15.) I started seeing things in the corners of my eyes, shadows. Like dark figures, of all shapes and sizes. I also have REALLY vivid dreams, where I can't tell the difference between that, and reality. And it's all places I've never been before, and I've read that psychologically, dreams can't be more than an real people you know, in real places you know. But, anyway, I used to have a reoccurring nightmare in an unknown house, but I could sense it was my house, and my room. Then a tall, skinny man in all black would just appear, and every time he'd say "hello, love" and I'd try to scream but he'd tackle me and cover my mouth. He'd say "screaming won't help" and stab me 4 times, then I'd wake up. I once told my friend, and she was psychic && she asked the creator to help me. And I haven't had it since. I um, I'm unsure if I'm psychic though because all the things I remember are either scary/negative. Or of my friend, Parker, He killed himself 2 months short of a year ago. And sometimes I hear his voice, and see him, but as a 20-30 year old. But I know it's him. I'm unsure if I'm imagining things or not. I also can sense everyone's energies around me. Like if someones hurt, I FEEL their pain, and I feel their happiness, anger, everything. It's like I absorb everyone's energies around me. Anyone able to help me figure this out? It's just strange because nothing ever started until around the age of puberty, then I'd see things, and a year ago I started sensing things. I also have an AMAZING intuition. Such as, one time my friend had decided to go shoplifting, normally I wouldn't care, and I'd shrug it off. However, one day, I KNEW she shouldn't go. It was just wrong, she waited 20 minutes then left anyway. By time she got to the store, at least 20 cops were there. They would've been there by time she was leaving with the stolen items. Then, again, I didn't mind what she'd do. But, another day, she had gone, and I felt the urge to call her and tell her to leave, so I did. She didn't listen. That day, she had charges pressed for shoplifting. Another time, (I know I've done a lot of bad things) Anyway, I had snuck out of my house, and every time I closed my eyes, I saw cops all around my house. By time I'd returned, there were cops there, and they had arrived about an hour after I had gotten those "visions".