First of all, it's super cool, but I totally understand the feeling of excitedly putting it on, looking in the mirror, and going "- oh." Do you not like the way it looks on you because all the bulk and color makes it looks too top heavy?
If you really aren't going to wear it as is (be honest, are you?) you might as well try putzing with it some more. You could maybe try dunking the whole thing in diluted bleach for a short amount of time to try dulling the colors to something that's a little more understated. I personally don't like belts with that sort of thing in general and it kind just makes the whole thing a little busier. I would just say tailor the shirt to you and go from there. Jeans that fit nicely or a slim line skirt (a short one?) would look good with it. Or cute shorts.
This all reminds me I need to rip some interfacing out of a shirt I made that's too stiff in the front. It was a recent "- oh" of mine. Also, I might totally copy you and do something like this. You could do something similar with the left over fabric from the shirt you cut down to size. I like it.
It's funny, after I wrote that I would probably never wear it, I tried it on with some skinnier jeans and a grey long sleeve shirt under, and I really like it. It's much busier than what I usually wear but I'm hoping to find an occasion. Thanks for the advice though. If you do that diluted bleach thing does it leave weird marks or spots or look like its been bleached?