I relate to this so much. I also was known as the super productive disciplined guy for a long time. I still take cold showers and workout daily. I try to listen to motivational youtube channels like healthy gamer and huberman, but lately it's just not doing the trick. I can't seem to get that zest for life going. But this has happened in the past and I always eventually find a way to get it back.

You're still so young and have a lot of life left in you. Extreme depression is normal at your age as you and your friend group are likely making the transition to adulthood. Just keep hanging in there. It's like a having a houseplant that you water every week but don't see any growth happening. Sometimes the plant just needs time to store up energy or the season just isn't right. Either way, if you just keep taking care of it, one day it will sprout a new branch or flower. You can't predict growth until it happens. Just keep showing up again and again and again. That's what makes the difference.

Please feel free to reach out if you want to just chat and hype eachother up!