Am I allowed to be depressed even if my life is “good”?

I’m a 15-year-old guy from Germany, and I’ve been struggling with this question for a long time. Objectively, my life is good. My parents are well-off, supportive, and loving. They give me everything I need. I’m not bullied. I have friends. Nothing “bad enough” has happened to me. I’ve never had a partner, but that’s pretty normal at my age. And yet… I feel depressed. Not the “sad once every few months” kind. I feel bad almost every day. I’m constantly tired even when I get enough sleep. I’m unmotivated, anxious, and scared for no clear reason. I have negative thoughts daily, and I genuinely can’t see a future for myself and thats been for about 4 years i feel like that. Everything feels heavy, like I’m just existing instead of living. What messes with my head is seeing people online who lost everything — family, money, stability — and they’re still standing strong. Meanwhile, I have so much, and I still feel empty. It makes me feel weak, guilty, and broken. Like I don’t deserve to feel this way. So my question is: Am I allowed to be depressed even if my life looks good from the outside? Does this make me weak? Why do I feel like this when I “should” be fine? I’m not looking for attention or validation — I genuinely want to understand what’s wrong with me and whether anyone else feels this way.