Yes, I can visualize things and hear them with my eyes open, rather I find it easier to do it that way but it makes me feel weird and anxious. Well, I already have high levels of anxiety since I was a child anyways.
I guess..it makes my limbs feel light? Another thing that happens when I get really anxious, so I drew parallels there.

It's not a superpower or nearly as impressive as it sounds, but yeah. It's not even close to what people might see when they're hallucinating.

edit: By "hear them", I mean I can imagine the sound it will make and I can hear it. I don't even know how to explain it.

What is your approach to art? Do you think you're analytical or intuitive?

Also, interesting read https://www.verywell.com/left-brain-vs-right-brain-2795005
Which is apparently said to be a Myth now? I remember it being a fad.
So, with things like this we should not really come to conclusions, I think.

On the subject of dreams, your website says http://aphant.asia/faq?catid=0&faqid=3

Also, one of their FAQ has a facebook comment section as source. Not very convincing.

I'd love to wait this out and see if their supposedly planned researches do happen, and what they find out.
I can see why it can give you bouts of depression. But you seem to be doing fine now, which is great. Don't complicate your life, man. You're a very good artist and I definitely look up to you, along with many others here.

Moving on..

I am able to visualize most things in black and white, like movements, patterns, boxes rotating, people turning, moving their arms etc, but it does take a little effort. Trying to imagine color is a little difficult, but doable.

What I found out is, this "visualization" mostly feasts on my memory and being able to recall things. The website tells you to visualize the contours of the face of someone who you see all the time. I tried to imagine my mother's face. I kinda could, but couldn't. Why? Because I never consciously decided to store that information in by head. Our brains filter out useless information all the time. I looked at my mom again and tried this again after an hour~ and viola, it was much easier.

Have you tried doing that? Seeing things and then visualizing them after some time? How did it go?

But yeah, please don't stress over this, if you are!

Keep trying, you'll be fine. Experiment with a few things. Look at more references. Look at backgrounds of the said arcade games. Don't be so dismissive of yourself! 
Looking forward to seeing an update.

It's much better, but can be improved greatly.

As the next step, I'd recommend looking up images of real swords and trying to get the size of the blade and hilt right.

The hilt is too long right now, I feel.

Just do it. Then you can tweak it to make it split and stuff later.