It does sound like depression. I’m not a psychologist though, maybe it is just apathy or indifference as you say.
My suggestion is put things in your calendar to look forward to. Do you have that already? A class you love to go to, a vacation coming up, or a night out with your friends.
Maybe volunteer doing something that makes you feel needed that you enjoy doing. I volunteer teaching zumba, because I like doing it anyway. I’ve thought about volunteering at the local elementary school.
You can also focus on happy times when they happen so they stretch out. Happiness comes in moments, and if you can notice the moments enough to truly recognize them and enjoy them, time moves slower in those moments. It’s much like the saying take time to smell the roses. A lot of times people gain this skill after they have been through a very difficult time, like a bad illness, but you don’t have to go through something awful to do it.
I’m so happy just being at home with my husband watching our favorite TV show in comfy pajamas and being warm. I spent years in pain, and being cold makes me feel unproductive and paralyzed.
Do you live in a place that is in winter now with grey skies for days on end? That could be adding to your apathy. Moving to Florida changed my life. Blue skies and sunshine. Last night I are al fresco for dinner and then danced a little (we have a live band and dancing here) in the fantastic weather. Even if it was cold outside, in my house the difference between 68 and 70 in my house is the difference between wanting to be buried under a blanket and having the energy to make things nice in my house and work on projects.
Also, if you are under 30, it’s been scientifically shown that young people feel more emotional pain. That as we age we are able to feel more happiness and ride out difficult times. So, most likely your future will be happier and have more meaning to you.
If you every feel like really being “done with it all” reach out to a therapist or suicide hotline or even a friend in that moment, don’t harm yourself. Most people don’t want to die, they just want to end their current situation. There’s a big difference. Things change, things get better.
Maybe see a therapist now. Maybe you are a candidate for therapy, or for an antidepressant.