Am I going crazy (teen question)?

I get sad sometimes and I dont know why.I have thoughts about killing someone, I would never do it but its like my mind is bringing it up but I say no and I would never do it. Most nights I hang out with my brothers who are all at home. I haven't gone out to hang with friends in about a month and a half, but before that, I was having the life. I was partying with friends and going out to eat, and just having fun and loving life. I stopped that lifestyle because I was smoking weed, but i've been off it for about a month and only did it for 2 months. Right now I'm kind of in a better mood. I'm always at home. I go to football, and I have friends, but I never ask them to hang out, because I feel like they would think like I NEED them and in a way I kind of do. My family life is fine, we are great on money and I work at my dads restaurant. I don't get much sleep at night, but now I'm starting to sleep more. Like today I took about a 2 hour nap. I dont know if its because I was into the social life and quickly turned away from it, that I'm feeling this way or I'm going crazy. None of my brothers felt this way and theres no one in my family that is crazy or even close to it. I don't know why my mind is doing this. My mom works for a psychiatrist and I can get a free visit, but my mom and I don't think I need that. Liek I'm acting scared of the world in a way. Is that because I'm always at home and bored. It feels like my house is like boring to me now. I really want an answer, and I don't think I'm going crazy but my mind is thinking it. I'm prety sure I'm a hypochondriac. I love my family and friends and still kind of love my life, but now I like it and not love it. I would never commit suicide, but my mind thinks about it. Like things are running through my mind. Is it because I only get liek 6 hours of sleep a night, or because I haven't hung out with anyone. Please I need help! And I'm also scared of watching anything sad, because it would make me scary. I used to love scary movies. I went out like once in the last 2 or 3 months, and had a lot of fun. Any help.