Am I depressed?

Lately I am always sad, tired, and I never feel good enough. I feel like none of my friends actually care that much about me and no one really likes me. I don't feel like I'm good enough for anyone, and people don't want/need me in their lives. I never sleep good at night. I have a lot of nightmares and wake up at least once during the night, but usually more. I always feel like crying for no reason, and I am always tired and never want to hangout with friends anymore or do anything fun. I go out and do stuff a lot bit where I do, I usually am just thinking about goin home to my bed the entire time. I also am constantly stressed out and anxious about small things. My uncle passed away in February and that could be part of it, but I don't think that's why I'm feeling this way. I took some tests online to see if I'm depressed or just sad and they saod that I have moderate depression, but I don't know if i can trust an online test. I'm 15 years old. Please give oppinions