Whats wrong with me?

Patient: I am a 20 year old male and when the sun starts to set, its the way the sunlight reflects off of everything, but I feel tired, and i reflect on life and look at my future and don’t see my future or life very interesting. but as soon as the sun disappears i feel better. i don’t know if that’s depression, but i don’t think depression only lasts that long. what is it?