I think my dad is kinda depressed now, do I really need to do anything for him?
Seriously though? You have to ask? Are you sure he's depressed?
Yes, you see I once saw my dad sad when he came to visit me from a business trip
Talk to your dad and see what could be bothering him in his life right now. If you can get him the help he needs, you might be able to stop some bad things from happening from his depression.
I'll only add more hurt to him. I'm gonna stay quiet and pretend I don't notice anything.
Well, you are aware he is depressed for one thing. You won't be harming him in getting him help, it doesn't work that way. Helping him will make him feel so much better and let him know someone cares.