I'd rather give you suggestions and let you do the editing
First of all, you need to tweak the palette; you have a lot of whit there that is overly-vibrant. MAybe:
1. Work some greys in there to give it some shape, which in tun makes it a little more understandable to the eyes (at least more understandable than a solid white shape burning a hole through the plane)
or
2. Adjusting your white to be either a slightly-grayed white or an off-white, both of which would be much easier on the eyes.
Also make sure to center your text -- right now it seems squished.
Along with shadows make sure to try and use highlights.
**Designate a light source, and make it apparent to the viewer!
And dont be afraid to work with colors that are desaturated; it helps add to realism.