"the dictionary meaning of that makes up a psychopath"
Just for starters I want to point out that if something fits the symptoms it doesn't mean that's the conclusion. This approach is like self-analysis using Google: finding out what is wrong with you and realising you fit 6 out of the 12 symptoms for cancer. It doesn't work like that.
I think I share some of your traits. I have only just gotten into reddit, so instead of going to /r/watchpeopledie I would go to bestgore.com for example. Same thing though, although I wouldn't say happy as much as excited or amused (and unlike you I am into the gore). I don't have strong emotional responses so I don't really feel happy ever as much as I manage to feel satisfied. But I wouldn't say I don't feel things, I definitely do, and I'm sure everyone does. The problem is being aware of it when it happens. Even if I were happy I wouldn't be able to tell. "i almost feel like I'm depressed but i don't feel sad nor happy." Same issue for me, but that uncertainty towards what you'd link that feeling to... For me it's emptiness, which then leads to depression if I do nothing about it. That's why I'm always doing something new to try to temporarily escape the emptiness.
See in my case, my psychopathic tendencies might just be caused by an emotional detachment, which would mean I'm not really a psychopath. When you say there's something that clicked? That probably means you're not a psychopath, you've just gone through an experience or a moment (however brief it was) that made you adapt and adopt some of the tendencies. Usually being a psychopath is related to something genetic, meaning you are born a psychopath (although I'm not entirely sure here and even if that is the norm, I would personally disagree to some level).
"Everyday I have these "fantasies" about killing people that i see." I'd say it's because you're missing something. If you think this isn't healthy for you, then do something about it. Force yourself to socialise, to meditate, to feel again... If these thoughts and mannerisms were natural then you'd be fine with them, and they wouldn't bother you. You wouldn't try your hardest to hate the thoughts.