I can't tell whether i'm depressed or just very lonely

I'm a 19M and I have a hard time telling whether I'm depressed or not. I do a good job of putting on a brave face on when I'm out in public. However, when I'm alone in my room, it feels like i'm living in darkness. I'm pretty observant and I've noticed that I have stopped wanting to look nice for myself. I've stopped looking in the mirror or checking myself out. I've stopped putting effort into anything. I stopped caring about how I smell, my aura, my taste, my voice, my speech. I don't even move anymore. I'm always just lying in bed. I don't care, i'm alone most of the time. I'm alone when I'm in class, I'm alone when i'm out in public, I'm alone when I'm with others. I'm just alone. I get very anxious thinking about leaving the house alone. Hell, I'm scared of going up to someone alone. I'm alone in a good neighborhood. But the thought of walking alone outdoors is terrifying. I'm alone in my room. I'm scared of being alone. I'm alone with my thoughts. I don't even talk to myself. I'm alone. I'm just alone. <br><br>TLDR: I can't tell whether I'm depressed or not. I just feel alone all of the time.<br><br>Edit: I was going to get professional help, but I don't have the motivation to do it. I'm just so tired of putting in effort. I feel like it will just be a constant cycle that will tire me out. I'm just so tired of putting in effort. Hell, I'm tired of living. I'm so tired of existing. I'm tired. I'm tired, I'm tired, i'm tired. I don't want to live anymore.