I just feel so empty and scared and confused?

I've just been feeling really empty and bad today. I don't know. Like I'm having a quarter life crisis or something. I mean I go to an Ivy league university, and I don't even know what the f**k I want to do with life anymore.
I just got into thinking about how numb we all are. How much I've lost touch with myself and any passion I ever had for anything. I just go with what I was interested in when I used to be interested in stuff. Not that I'm not interested in things now, just I used to be passionate. Now although I have interests, I only have fake passion.
And I got to thinking; is it me who is numb? Or is it my entire generation? Because I can't remember what feeling feels like exactly. That overwhelming joy, or extreme sorrow, or passion and creative drive. I feel like we're always stuck on Facebook and our iPhones and can't even feel anything but materialistic joy anymore. Or maybe it's just me who is numb. I really don't know.

But if I don't keep busy 24/7, I feel like I lose my grip on things. I think too much. I get lost, I get confused. But when busy, I feel like I have no time to think outside of school/life tasks, and I just long for some time to figure out what is going on.

I feel like I'm on this fast moving train. I don't know where it's going, I'm just trying my best to go with the flow, but it's going so fast and every moment I slip back a little more, and all I really want is to slow down so I can figure out where the f**k I'm going.

I don't even know who I'm anymore though. I feel like I'm defined by the way other people see me, and I have no definition of myself. I look in the mirror sometimes and I don't even recognize my reflection as me.

As a side note, I've been super paranoid lately. Like before I go to bed I check behind the shower curtain to make sure no one is there, I deadbolt my door. I'm always afraid people can read my thoughts, or that everyone hates me and they'd rather I not be with them. I mean it's probably normal stuff for someone my age (19), but yeah.

What is going on with me? How do I feel "normal" when I'm not keeping myself busy with empty tasks?

This appears like a typical problem of growing up in adolescents compounded by the stresses of fast living in the society today. You may like to try dose of a homeopathic remedy called Alumina 200c and see if this helps. Alumina is known to help in such stages of life when one feels lost and confused about one's Identity among other things. It just might help you as well. If not, feel free to contact me

Set some goals. Maybe start working out or jogging 5 days a week, goals with grades, etc.