Why do I want to be depressed?

Hello, lately I'm feeling really depressed and I just don't know how to handle it anymore. Two days ago I cried for a few hours straight and couldn't stop thinking about how pointless life actually is. We're born to go to school, so we can get a job and make money, then we retire and just wait to die. Of course it's a lot more complicated in real life, but I can't help but see it that way. I'm only 18 years old and just started university, but I feel like I just can't do it anymore. I'm tired of everything and don't see the point of living, breathing, lauging, studying, talking, etc. What's the point of literally anything when I'm gonna die anyway, why would I even bother? When I'm dead, nothing matters anymore. I don't understand why I can't just die right now already, I don't see any difference. That said, I really just felt like just taking a knife and cutting my skin to pieces, I didn't do it because it would hurt my mother so much, she's like the only reason I just can't do it. It really felt like I detached myself from everything, like my aunt could die that day and I would be like "okay, that happens, I don't care", I just felt like nothing wasn't real anymore, that life is an illusion and that nothing or no one could touch me anymore. As you may be able to understand now, this was really a terrible day where I just couldn't handle the depressed thoughts.

The next day, though, I woke up, and everything seemed to be just fine. I just had a totally different view on everything again and I could function properly. I wasn't happy or anything, I was just fine, alive and well and even tried to study a bit for my finals. But then I had this feeling that I didn't like to feel that way, I wanted to feel like the day before, I wanted to feel detached from everything again and cry again and I wanted to feel like I wanted to kill myself again. I started thinking about really negative things, hoping I could feel bad again, but I just couldn't get myself as depressed as the day before, although I desperately wanted to. I know this may sound really weird, I should be happy that I had a day where I didn't feel like killing myself any second, but I just didn't, I "liked" that feeling of being hopeless. It made me feel in control of the life I hate so much and made feel like "okay, if I can't do it anymore, I can just kill myself any minute, nothing or no one is real, it's just an illusion, you love no one and no one loves you, so it's okay to kill yourself" (besides my mom then).

Is it normal that I want to feel that bad again? If I feel like that, will I ever get better from my depression? Maybe I'm just made to be depressed, just like other people are made to be happy. Depression may be my state of "normal" when for others it's an illness. I just don't know anymore and wanted to know if anyone else feels this way. Or maybe anyone who agrees with me on the seemingly pointless life we're all living when we could literally all just kill ourselves right now and humanity would just be gone, no more problems to be solved, no more diseases, no more nothing, wouldn't that be better for everyone?

Thank you in advance, I hope you're all doing well.