Am I Pretending to Have Depression?

I just got done with listening to my dad talk to me about work. I let on I was being late to work pretty regularly by a couple minutes (this is a half truth. I didn't tell him that I was late by at least ten minutes semi-regularly and I haven't been on time for a couple weeks).

By the end of our discussion, he told me that he was sick of me being in such a mood and that I should just cheer up. We're in good financial circumstances and there's opportunity so I should just suck it up and be happy already.

The thing is that I guess I could be depressed? I'm too happy though. I laugh at least once every day, I genuinely smile sometimes. But I go to work late almost every single day because I thought, I had more time to sleep that morning and I curse myself out on the way there to the point that if I afflicted such speech on anyone else, it'd be abuse. I'd be in a light mood during the day and I go back home. On the way home, I'll chastise myself heavily about either the lateness or some mistake(s) I made. I come home and I'm either in an okay mood and delighted by videogames, a movie, or a book. Or I come home and I don't feel any will to eat.

Last time I took a shower was last week. The only reason why I brush my teeth kinda regularly is because I speak repeatedly. And my "scent" has been covered up enough judging by the lack of disgust by the people around me.

I fear going back to college. I'll be going in the middle of this month and just thinking about getting graded for anything is stressing me out. Why? Grades are a bad thing for me. I don't do well in school anymore, haven't since elementary, and I'm super frustrated with myself for that. But no matter how many times I hit and give myself pain, I don't change. I'm pretty worthless.

Not a week goes by without any thoughts about my own death or demise. For the last, uhh, four or five years I think, I've been wanting to die generally. For the last year, by my own hand. For the last month, hoping I'd deliver that wish same-day.

But I don't feel tired all the time. Nothing feels particularly grey. It all seems fine.

Am I faking it? Am I a poser and is my dad right? Am I just too lazy to get up and get happy?